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> Precision long range hunting and shooting
> Powders, load development
Powders, load development
@ 10:41 am (GMT) |
jasonIv just started load development for a 22br.I'm using 2208 with 80gr projectiles. Iv got a funny situation where the first lot of increases in powder weights shot real well five out of six groups were .25-.3 inch groups at 100. I though wow this is great. But velocity is low. About 2850-2900. Iv since been up to about 3200. Which may be too hot, slight ejector mark. And being hot at 3200 poor groups were to be expected. The whole way es was fairly good. But so far I can't get any decent groups in between 2900 and about 3150. There's not much load data around for this, but one piece iv seen shooting 90's said varget or 2208 shot well at low pressure but the guy needed another powder, I forget which, to shoot well at higher pressure. I think it was a bit slower. Would this make sense in my situation? Is a good or bad powder dictated more by pressure than the components used to make a load? I think I have enough room for 2209. But iv also had a guy suggest benchmark 8208 which is quite the opposite in burn rate But is supposed to work well with about 30gr which is where I'm at or a bit over with varget. What does the science or theory say behind powders? Is it normal that my 2208 loads would seem to act this way, accurate at low pressure but not high pressure? |
Replies
@ 06:53 pm (GMT) |
Nathan FosterRe: Powders, load developmentHi Jason, it really comes down to the individual harmonics of the barrel.In this situation, the worst case scenario would be to have a sudden drop in pressure as the bullet reaches say 24" but still has some way to travel before exiting, causing irregular harmonic vibrations at this point. To this end, using a 2209 / H4350 may help when launching the heavy pills. I do however understand why someone would want to try a faster powder. Over the years I have found 2206H to be very responsive with meaningful changes in results in many chamberings. It is akin to hitting a steel part with a light but extremely fast hammer stroke rather than hitting it with a slower heavy hammer (hopefully some of you will understand what I am driving at here). To be sure, changes in neck tension and jump can also effect harmonics. It is also common to see guys using Hornady FL BR dies (including bench rest comp shooters) which produce poor concentricity and force the shooter to back off loads as a means to decrease yaw. The shooter is unaware of any of this - he only knows that he has to back off loads to obtain accuracy but not why. The tail wags the dog. For now, go on as you have planned to do. Try 2209 and do make sure your ammo is concentric. |
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@ 09:02 pm (GMT) |
jasonRe: Powders, load developmentThank you Nathan.I do have 2206h, and use it in the 223. And it has worked well. That did cross my mind. I have a few more test rounds to shoot around promising slower groups from previous. But I'm not too confident. And will try the 2209 maybe even 2206h after this. I will look at concintricity again. But I was some what disappointed with it last time I looked. This is a tight neck, And iv seen better from factory rifles. Thanks again. |
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@ 04:44 am (GMT) |
jasonRe: Powders, load developmentI have brought more powder today and found my die is inducing 2 thou run-out with out the expander in it, and 4 to 5 thou with it in. So I'm going to try a type s bushing die. |
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@ 05:06 am (GMT) |
jasonRe: Powders, load developmentOh, Nathan. Can you please give me an idea where to start with 2209 and benchmark 8208?I have no data, but varget was fine with 25-32gr. Well 32 was max. I'm just a bit unsure what faster and slower powders do or act and therefore not sure how much roughly to add or subtract from varget start points. Thank you. |
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@ 08:15 pm (GMT) |
Nathan FosterRe: Powders, load developmentOK, I would say concentricity was the problem and the reason why the loads decreased in accuracy with increased speed.You should be fine to use the same start loads as before with 2209. The sweet spot may be where your last max load was with 2208. I have not spent enough time with 8208 to be sure on this. My GUESS is that 26 grains will be near max. The same goes for 2206H. You may find that a change in dies is all you need rather than a change in powder. Suggest you re-try some of your previous loads, try 2209 also. Use a fast powder as a final resort if all else fails, simply to effect a pronounced change in harmonics. You may however have to sacrifice some velocity if you do this. |
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@ 08:36 pm (GMT) |
jasonRe: Powders, load developmentThe new die is here, but it doesn't seem that much better. The bushing is sizing down too much, a 248 is about 265 so iv ordered more. And concentricity was hit and miss. The Wilson bushings have a taper. I'm trying to run numbers down in the die, so sizing the neck is one size without the taper. I shot the last varget rounds from a medium velocity up even with another bullet, I can see the cut off point. Will try 2209.Thanks Nathan. |
@ 06:00 am (GMT) |
mark whiteleyRe: Powders, load developmentHi Jasonfrom the sierra manual, 22 br 26" barrel, 1x8 twist, coal 2.160, 80gr smk, 3000 fps, 28.3gr 2208 hope this is of use kind regards Mark |
@ 06:48 am (GMT) |
Mike DavisRe: Powders, load developmenthere is a thing to try...it works for me,shown to me by chap who taught me about reloading and has been tried and prooved sucessful by otherswhen seating bullet,start bullet into neck then revolve case aprox 180 degrees then continue seating stroke...... nothing to loose giving it a go..... |
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@ 10:14 am (GMT) |
jasonRe: Powders, load developmentThanks mark. Iv seen that, it's a fair bit out. I get about 2850 with about 28gr and I'm maxing about 3200. I will settle for 3100/ 3150. In saying that a good 3050 load will do.I normally do that Mike. My issues are in sizing the brass, I will look more closely at seating, after sizing gets better. But thank you everyone for your input. |
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