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Forum Index > Rifles general discussion > Rem Sendaro 7mm load dev issues/headache

Rem Sendaro 7mm load dev issues/headache

13 May 2015
@ 04:54 am (GMT)

Rad H

Well, ill start off With saying. Nathan, what you've put together on this website is absolutely amazing. The books are even better. You've done the world a favor. Keep up the good work.

Anyways, i bought a sendaro and put a 6-24x50 vortex on it. Went and bought a box of nosler brass and 162grn SST's. Made a batch of test bullets. CCI 250 primers, 3.329 OAL, started off @ 63.5grns and went up in .2grn in rements to 66grns. All fired fine fps increased at close to 20fps per shot.. Over an RCBS ammo master chrony. These first shots i was only trying to get the gun a bit closer to center after i bore sighted it and was looking for pressure signs. Hopin to find max or near.. Drop a few points and then start playing with seating depth and go for tight groups. Well after shooting 60 rounds so far. I have 3 reloads on 20 of my cases.. Worked my way up to 71grns.. Book max says 65.. Not too worried about it.. But what has bothered me is this. I have no signs of pressure. No craters, no scuffs, no ejector marks, no stiff bolt nothing... Ive tried another batch of 7828 just to b sure. Fps stopped climbing @ 67grns... Above that all its done is jump inconsistantly between 2880 and 3060 and everywhere in between.. No steady consistant loads... Ive reloaded for both a .270 and a 270 WSM and neither have acted like this... Ive never loaded for a belted case before. I understand sizing brass and was neck sizing these loads with a lee collet die with the intent of letting it grow until there was issues... Then full length size.

Im stumped.... Any ideas?!?!?

Replies

13 May 2015
@ 04:58 am (GMT)

Radley Hodgson

Re: Rem Sendaro 7mm load dev issues/headache
On a plus side, other then a few fliers on my part... The rifle is grouping very well at 100yrds...
13 May 2015
@ 07:01 am (GMT)

chris murphy

Re: Rem Sendaro 7mm load dev issues/headache
Nathan will have a good idea on this but the random velocities you mention could be brass veriation ie neck tension/ neck thickness. Also the spacing to your crony. Too close will give random results. Just a thought. But Nathan will know
13 May 2015
@ 07:03 am (GMT)

chris murphy

Re: Rem Sendaro 7mm load dev issues/headache
Oh and scales... Electric scales with your phone too close can throw things out
13 May 2015
@ 01:00 pm (GMT)

Radley Hodgson

Re: Rem Sendaro 7mm load dev issues/headache
I use a balance beam type scale... And i always check it with 3 different weight bullets before using. The batch of 7828 was in a can... So i bought a new batch of 7828, in a jug. no difference.

I dont see how neck tension could be off, i litterally have changed nothing since initial setup. Unless the slight dab of case lube i smear on the case necks prior to seating is doing it? Which made no difference at all on my WSM
13 May 2015
@ 01:02 pm (GMT)

Radley Hodgson

Re: Rem Sendaro 7mm load dev issues/headache
I have the chrony stretched out as far as the cords can reach, and i drape a sweater over top of the sunshades so that it is boxed in pretty good. New battery.
13 May 2015
@ 09:41 pm (GMT)

Nathan Foster

Re: Rem Sendaro 7mm load dev issues/headache
Hi Radley. First a warning to others, the following pertains to this rifle only and could or will prove unsafe in some rifles.

With that out of the way...

Am glad you enjoyed the books Radley, thank you for your kind comments.
Obviously I am going to be guessing here- not much else I can do from halfway across the planet.

Firstly, could you please refrain from lubing the inside of the case necks prior to bullet seating. I just want to make sure that everything is uniform and that any results you get can be extrapolated with normal data where lube is not introduced as an extra step. I just want to remove this as a variable.

The remaining variables might include:

Bore condition (barrel may not be fully broken in- even though round count is now 60 rounds).
The type and batch of bullets- the SST can sometimes be finicky.
Bolt locking lugs.
The type of light reaching the chrony. The DISTANCE of the chrony.

I suspect max will be around 74gr in this rifle but cannot say for sure- not as far as safety goes. You may if you want to, continue up to 73.5gr, looking for sweet spots around 72 to 72.5 grains while watching for pressure.

Set your bullet jump at 10 thou for now. If you are currently using a longer jump and take this advice and seat forwards, back off loads by 1 grain and work up again.

Could you please report back to me on the rate of copper fouling. The throat may still need a good polish.

Check locking lug contact as per my Accurizing book.

Is there a possibility of testing the rifle on a cloudy day- no shirt over the chrony. Make sure the chrony is set 13ft away, regardless of cords.

Make sure your primers are stowed in a very dry area / container, not just sitting in a shed.

Is there a possibility of working up a batch of loads with the A-Max, half grain increments, 10 thou jump again. You do not need to start back from the beginning as this is a softer bullet than the SST. You can start at 69gr if you prefer.

Finally- before we get too far ahead and start twiddling with loads or the rifle, could you please let me know the type of accuracy the rifle is currently producing when shot over sand bags or a V rest, using a traditional forend hold and sling. If the rifle is accurate, I may be barking up the wrong tree with such variables as bore condition. It may indeed be a unique set of circumstances with regards to the way the chrony is reading- if the rifle is accurate. There is normally some correlation (if not great) between the two.

A bit of homework for you. Hope it helps.
14 May 2015
@ 02:18 am (GMT)

Radley Hodgson

Re: Rem Sendaro 7mm load dev issues/headache
Other then the odd flier, the rifle is grouping well. I've been shooting prone on a sleeping roll. With a jacket bunched up under the butt and my pack under my forearm, sling wrapped around my forearm. Same as i would in the field if givin the opportunity. I recently bought a set of bags to continue testing as well as some 160 and 140grn partitions. I will do as you suggested and refrain from the lube on my next batch of rounds. Chrony was at approx 20'.... I have shot over it in the morning on a calm overcast day, a bright sunny day mid afternoon and a breezy evening. I also shot some factory 130grn nosler e-tips out of my WSM over the chrony on the last session and all 5 rounds were between 3190 And 3240... Right on the money for factory rounds. i also have a host of powders on hand to try including 4831ssc, H1000, 7828ssc, retumbo, IMR4350. I have a brick of primers all my supplies have been stored inside, in a basement that is cool and dry.
14 May 2015
@ 02:28 am (GMT)

Radley Hodgson

Re: Rem Sendaro 7mm load dev issues/headache
Bore seems to foul slow and steady. Conciderably less then my x-bolt 270wsm... Accuracy doesnt seem to change, although when it gets hot (hot afternoon on a 5 shot string) it did walk to the right approximately an inch... Ive used the same table top as a target everytime with the targets held in all 4 corners by screws in the same holes... All 60 rounds have punched through a 4" diameter hole except a couple attempts at hitting a large fly that was landing on the paper(i got distracted)

I have not bedded this rifle yet, i know u suggest doing it all before shooting but i wanted to work up a decent load and see how it behaved first incase it was a lemon so i cud sell it if need be. Im pretty impressed so far and i have one of your bedding kits sitting in my room. I did the stock stabilize and re-bedded my browning and had excellent results.

Thank you for your time nathan, ill relort back after my next range session

15 May 2015
@ 02:06 am (GMT)

Radley Hodgson

Re: Rem Sendaro 7mm load dev issues/headache
hornady 162grn SST lot# 2131336 batch appears to be 32813 the 8 is hard to make out.
15 May 2015
@ 04:24 am (GMT)

Nathan Foster

Re: Rem Sendaro 7mm load dev issues/headache
No worries Radley.

By the look of things, we can hopefully take the rifle out of the equation, apart from the lugs perhaps. The chrony can be pulled from the equation too.

This leaves us with load variables which will include:

Pressure
hand loading technique (omitting lube step)
Neck tension- variations.
Projectiles / batch or bullet style versus the bore.

If you want to try some loads with H1000, you will be able to start at 70 grains based on what you have told me so far about the other loads. But you may wish to see things through as far as finishing current load work goes. Call this plan B (or C if you change projectiles first).

Neck lube might be a key factor in the first instance so lets see how that plays out.

If playing with the Partition, set seating depth at 20 thou jump. Move to 40 thou if results are poor. Sweet spot for the 160gr possibly around 3060fps or more.

18 May 2015
@ 03:56 am (GMT)

Nathan Foster

Re: Rem Sendaro 7mm load dev issues/headache
Hey Radley, just had a thought. On your checklist (write it down somewhere or refer back to here), please add main spring tension / Ignition.

Could be a (rare) dodgy bolt spring. I have chased this in the past and in the Remingtons, it usually actually makes bugger all difference swapping springs. More often I find problems with the new welter weight rifle brands and undersized POS springs. Regardless- add this to your list- at the end.

Possible check:

Ignition assembly and main spring.

Preliminary check- thickness of lube on existing spring (gumming?). Change to light lube.

Or- change main spring if problems persist.

18 May 2015
@ 08:11 am (GMT)

joshua sutcliffe

Re: Rem Sendaro 7mm load dev issues/headache
Hi Radley, Looks like Nathan has covered quite a bit here the only thing i would add is to actually shoot the rifle at some longer range if possible, 700+ metres and that will give a very good indication of velocity and therefore its consistency.

Josh
19 May 2015
@ 11:07 am (GMT)

Radley Hodgson

Re: Rem Sendaro 7mm load dev issues/headache
could this be a headspace issue?

Fps seems to get flaky in the higher pressure loads, like after a certain point it just "leaks" not quite sealing off the chamber.

Everygun ive ever loaded for personally seen loaded shows pressure signs when the time comes. This thing shows no signs and just starts spitting bullets at variable fps.
19 May 2015
@ 08:31 pm (GMT)

Nathan Foster

Re: Rem Sendaro 7mm load dev issues/headache
Hi Radley, if it were head space, the lower loads would be failing to obturate while the hotter loads would create a better seal. Regardless, as long as you neck size, the fireformed cases will correct head space issues unless there is a dire problem.

As far as pressure goes, you may be above book max but that has no bearing on whether you have reached full pressures. Could be a way to go yet.

Uneven neck tension due to variations in temper is another potential issue with regards to ES. If you are using Win or Rem cases, you will start to see split necks as an indicator. Tricky business though as manual annealing operations are not exactly 100% uniform when it comes to temper. I put my notes on this in the reloading book.

You'll just have to keep plugging away at it for now. Carry on with pressure testing and we will see what happens.
31 Jul 2015
@ 01:13 am (GMT)

Radley Hodgson

Re: Rem Sendaro 7mm load dev issues/headache
rifle now has 165 rounds down the tube. found max pressure @ 73grns of 7828/250 primers and 3.365 COAL, measured tip to tail

action is now bedded and i gave the throat a good polish with poly roll and cleaned it VERY thouroghly....

switching to CCI 200 primers has leveled my fps spread quite a bit, but im having a hell of a time finding a load that shoots consistantly

running into issues with brass size now... its getting caught in the chamber.. empty unprimed brass and i have to smack the bolt with my palm to get it to pop open... run it through a FL die... unchanged.

had 1 case loosen up the primer pocket enough that i binned it and a few others... i now have 19 Nosler cases 6 reloads on them, and 20 FED nickel plated with the original firing and 1 reload.


im beggining to doubt my choice on a belted case... seems to be nothing but a pain in the ass so far

latest trip to the range saw 63grns of H-4831SC with CCI200 primers giving between 2812-2850 fps... but no groups as it was windy as hell
31 Jul 2015
@ 04:40 am (GMT)

Radley Hodgson

Re: Rem Sendaro 7mm load dev issues/headache
just loaded up and shot 10, in new cases. did nothing but primed, charged and shot them. 3.328 OAL, same as original loads. 70grns of H1000 over 200 primers.... 2810-2860 fps, adjusted scope as POI was off having swapped out my leupold rings/bases for a Nightforce -20MOA 1 peice rail.

it's grouping tight again... obvously the problem is in my brass.

now it seems i need to go buy a body sizing die...

so much extra work and $ for a belted case
31 Jul 2015
@ 05:12 am (GMT)

Warwick Marflitt

Re: Rem Sendaro 7mm load dev issues/headache
Buy a Toyota car (30-06) and you pay for gasoline and tires! Buy a Ferrari (Belted Magnum) And the bills get bigger and moreover you get to them faster? Can you get a Sendaro in 30-06?
31 Jul 2015
@ 06:33 am (GMT)

Thomas Kitchen

Re: Rem Sendaro 7mm load dev issues/headache
don't think you can warwick and toyota's have gone to the dogs in my opinion my work van roof has started rusting and my boss's hi lux deck is rusting, these are new vehicles.
radley what country are you based in? i know you can hire go, no go and field gauges here in nz to check chamber maybe?

sounds like you have learnt a lot but unfortunately a lot more to go yet.
who ever said education was free was a liar
01 Aug 2015
@ 02:10 am (GMT)

Radley Hodgson

Re: Rem Sendaro 7mm load dev issues/headache
Was probably just spoiled with my xbolt finding 2 loads so easily with minimal issues using recycled fed brass. Mind you ive tossed a bunch of cases out due to loose primer pockets. Oh well, its part of the game i guess. Im in canada. 30-06 eh.... Nah, im a big .27 cal buff... Probably shoot this barrel out then go with a non-belted .27 wildcat throated for the matrix bullets
01 Aug 2015
@ 10:33 pm (GMT)

Nathan Foster

Re: Rem Sendaro 7mm load dev issues/headache
Hi Radley, don't blame the belt, this has nothing to do with the issues you are seeing.

For starters, the brass you are using is a pain in the ass, both Nosler / Norma and Federal. Both are weak in 7mm rem Mag. If possible, change to Win brass.

If you continue to have extraction issues, it will be a primary extraction problem with the action, not a brass issue. Or- it could be a reloading method issue. None of this has anything to do with the belt on your brass. The area just behind the shoulder of your case is more of a concern.

Sorry, I have lost track of this thread so the next info could be moot. There is a chance your neck die is extruding cases or shoulder bumping and widening the diameter just behind the shoulder.

Suggest you try the Lee ultimate die set for this. It comes with a body die. You can drill out the neck area of the body die if need be so that you can size the body without losing and concentricity.

Possible steps:

Careful with blame allocation. Let go all assumptions as these are doing you no good.

Look at reloading methods.

If primary extraction is at fault, bolt handle may have to be shifted forwards to increase camming power against the rear of the action. Could possibly talk to PTG about an entirely new bolt. That would be the quickest route.

Empty unprimed / unsized brass won't cycle? Possibly both a very tight chamber combined with poor primary extraction. case goes in with a tight fit but won't come out because there is no camming power. The rifle may need to go to a gunsmith to have the headspace checks and primary extraction explored.

My hope is that the answers are quite simple. It may be that small things are causing problems. Well thats what I am hoping anyway.
02 Aug 2015
@ 06:47 am (GMT)

Jacob Jenson

Re: Rem Sendaro 7mm load dev issues/headache
Just want to share two problems i have dealt with a couple of years ago;

I once pollished the barrel on my 308 with something called Gold Medallion. After using it, I cleaned the bore and chamber, and finally lubricated the bore (not the chamber). 14 days later on a hunt i suddenly couldnt extract fired cases. I learned that the Gold Medallion had degreased the chamber and left it exposed. I found a very fine layer of rust in the chamber.... not good!

Can it be your problem in this case after all the cleaning. In your first post you shot 60 rounds without any problems....

The other thing I have learned is that CCI250 primers can be a pain in the a...!!! I have had several CCI250 that failed to ignite. I have also learned that ES i higher when using 250.

I would recomend using Remington 9-1/2 Magnum primers - they have never failed and shows great ignition and low ES compared to the CCI 250

J.[b]
03 Aug 2015
@ 01:02 pm (GMT)

Radley Hodgson

Re: Rem Sendaro 7mm load dev issues/headache
As my brass has grown, its seemed to have gotten worse... I didnt FL size until the issue started to show up. Just neck sized. The brass that im havin a hard time cycling has been fired 5/6 times, neck sized all but the most recent firing. And after playing around it seems as though the bolt isnt catching enough at the back of the action. At this point im ready to take it in to get the action blue printed and inspected.

Ill keep an eye out for some Win brass, shouldnt be too hard to find.

Im patient, ill pick away at this project till i get it shooting.

Trust me, im running CCI primers only out of availability... I prefer Federal primers... Remmy primers here are just as bad as the CCI's, i too had a bad batch with a bunch of dudes... That and they are ver inconsistant
03 Aug 2015
@ 09:41 pm (GMT)

Martin Taylor

Re: Rem Sendaro 7mm load dev issues/headache
I've said this many times on here Radley….. I F/L size my 300wm every time because of chambering/extraction, l hate having a stiff bolt feel. I use the Redding body seizer then the bushing neck die, works a treat only just bumping the shoulder but it's an age old debate hey, N/S v's F/L.
I just want my hunting rigs to work with no issues when l cycle, period!

As for the primers l use the Fed 210M Gold under Nathans instruction and have had zero problems using them on 5 different calibres and is now the only large rifle primer l use.

You could try and a soft scotchbrite of the chamber with some polishing paste (Autosol or Jb's), sounds a bit extreme but worked a treat on my 308 Rem & also de-burred/polished my new 06 the same way! I just cut a slit in a length of stainless tube and wedged a patch of Maroon scotch in it. But gently, gently hey, you only want to polish staying inside the leading edge.
 

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