|
|
|
Discussion Forums
Forum Index
> Precision long range hunting and shooting
> Length of barrel
Length of barrel
@ 07:49 pm (GMT) |
Richard WeidemannI'm planning on building a .270 Win. based on a Mauser '98 (VZ24)action. I read the article by Nathan on the .270 ballistics and performance and liked what I read. I already have a Ruger M77 in .270 Win., but it has a 22" barrel, which I've always thought was too short.While reading the article by Nathan, I saw that he recommended a 24" barrel. My question is whether or not a 26" barrel might extract even more speed and accuracy from that cartridge, or would it be so inconsequential as to make the extra length not worth it and the 24" barreled gun more handy and perform just as ell as the longer barrel? I'm not planning on any close-range woods-type work, more the open terrain stuff. I also believe that the .270 Win. will be more than adequate for my needs, and plan on developing hand loads for it. Any input would be appreciated. |
Replies
@ 12:02 am (GMT) |
Thomas KitchenRe: Length of barrelhi Richard.are you a hand loader? im not sure if you would get any extra speed out of a 26" barrel but it may be worth experimenting with one with slower powder to see, its not much for a gunsmith to knock it back to 24" and recrown it later. also please check how much length you can get out of your mauser magazine/action as you may want to look at throat length of the reamer that's going to be used. |
|
@ 06:59 am (GMT) |
Richard WeidemannRe: Length of barrelThomas, pardon my ignorance, but what do you mean by " check how much length you can get out of your Mauser magazine/action as you may want to look at throat length of the reamer that's going to be used." ? |
|
@ 08:27 am (GMT) |
Thomas KitchenRe: Length of barrelhi Richard ill do my best to explain but this is where Nathan's books are ideal and covers this better then i ever could.the standard mauser actions/magazine are not very long, you can fit a 270win in them if your using saami spec over all length, the issue you have is if you want to use a long projectile like a 150gr sst to still have it fit in the magazine you'll have to seat your projectile deep in your case neck, this in itself may not be an issue, but if your throat is long the jump before the projectile engages rifling maybe an issue when trying to get the best accuracy you can out of your rifle. if your not currently a hand loader all this might be bit foreign to you. i pulled out my mauser (parker hale/fn 308win) to check if my 270win hand loads would c.o.a.l of these are 84.7mm (150gr interlocks) they are to long to fit in the magazine, these are what i use in my tikka, i know these are not close to the rifling in my tikka as i did check, now if wanted to put a 270win barrel on my mauser and use same reamer as my tikka was chambered with im now even further away from the rifling because of the short mauser magazine. sorry if this is confusing you even more someone else might explain it better then i can. these things may not be a deal breaker but it is useful to consider everything if your trying to squeeze every last bit of accuracy out of your rifle for long range shooting. you also can modify a mauser action and magazine to get more length but this is another thing to consider and talk to your gunsmith about. |
@ 07:27 pm (GMT) |
Nathan FosterRe: Length of barrelThanks Thomas, I have been meaning to get to this.Hi Richard, your mag length is 84mm but you will need to seat to 83mm for smooth feeding which as Thomas has explained, will cut down capacity a bit (bullets have to be seated deeper) and may cause an extended jump. A long jump means that the bullet travels a long way before engaging the rifling which can (depending on your hand loads and each individual rifle) have a negative effect on accuracy. The magazine can be altered if you wish, however the easiest solution is to adopt something like the .30-06 which can utilize shorter COAL's. Have a look at the .30-06 in the knowledge base and see how this sits with you as an option. If you want to shoot open country, I promise you will be happy with an 06. Have a look at Bob's exploits with his rifle, he has also posted photos using the A-Max (actually bulk buy Zombie Max) within the last couple of weeks. |
|
@ 08:52 pm (GMT) |
Richard WeidemannRe: Length of barrelThomas and Nathan,Thank you both for the replies. To answer your question, Thomas, yes I'll be hand loading. I'm new to it, but I understand the ins and outs. And of course, a couple of good manuals will be essential. Also, I understand perfectly now about the magazine length. I'll be purchasing several of Nathan's books to help me make my decision. I'm not absolutely set on .270 Win. chambering, and if an '06 would suit my needs better, I'll take it into serious consideration. As an aside, is there a way to safely grind material off of the full length Mauser magazine and/or feed ramp so that a longer AOL length .270 round would feed reliably? All that being said, I'll get back to the barrel length question. It seems to me that, if the right powder is used in a long enough barrel, velocities could be kept up while keeping chamber pressures within a safe range. Obviously, there's a point of no or diminished return regarding length, but 26"strikes me as a potential good balance for barrel length and maximum accuracy. Thoughts? |
|
@ 09:01 pm (GMT) |
Richard WeidemannRe: Length of barrelIn the last sentence, I meant a good balance between handiness and maximum accuracy. |
|
@ 10:49 pm (GMT) |
Thomas KitchenRe: Length of barrelHi Richard.I'm typing off a smart phone while trying to quickly eat my lunch so have to keep it short. Don't think of barrel length as accuracy its velocity as Nathans 20" 308 is testimony to that. Barrel harmonics is where your accuracy lies and this is where hand loading comes in as you can tune your harmonics. Have look through knowledge base think there is an article on accuracy in there. I really think Nathans books will help you out a great deal as they sure did for me, the reloading will be just what you need to if your going to give it a go. |
|
@ 11:14 pm (GMT) |
Richard WeidemannRe: Length of barrelThanks for all the input Thomas. Harmonics relating to accuracy makes sense. I'll get the books from Nathan so I can make an informed decision. Also, I'm thinking barrel length in terms of velocity and load development as the accuracy part of the equation. I also have a Ruger M77 (original tang safety model) in .270 Win. with a 22" barrel. The pipe is still in good condition and it shoots fairly accurately, though I've never benched it, nor have I truly tested various loads to find it's accuracy potential. And again regarding barrel length, 22" has always seemed too short for that round. Is there any opinion on whether the M77 action is worth re-barreling and otherwise accurizing? I'm trying to build a rifle on a bit of a budget by using what I have and do as much of the work myself as I can. Or do Nathan's books get into the specifics of that sort of thing? |
@ 01:35 am (GMT) |
Martin TaylorRe: Length of barrelHi Richard,Nathans books get right into detail with regards to the how's and more importantly the why's. Both generically and to individual makes, models and calibres, pro's and con's, realistic expectations, true costs etc. Once you have had a read through you'll be able to make a informed call on a particular set up and find/make the right combination. ie; Nathans recommendation of the 06 to suit your Mauser action length over the 270. Now you have thrown in a M77 which l'm fairly sure has a generous mag length to suit either. All things covered along with questions you haven't gotten to yet! |
|
@ 07:07 am (GMT) |
Thomas KitchenRe: Length of barreljust my opinion so don't take it to serious (my wife never does)step1 get Nathans books step2 test your ruger with factory ammo step3 bed/stabilize rifle step4 test again step5 if above steps go well start reloading once again using steps set out in Nathans books step6 now that you got more knowledge and experience under your belt look into mauser project and consider all options including 30.06 and 284 win step7 enjoy all above steps and keep us posted on how things are going |
|
@ 09:06 pm (GMT) |
Nathan FosterRe: Length of barrelThanks guys, yes, the books are aimed to answer these questions.Just briefly: The Mauser mag box can be cut off at the front. The font of the action can be milled forwards. Following this, a piece of sheet metal can be glued to the inner stock to act as your new front for the magazine. These mods allow the M98 to be taken out long. However, not many people are that willing to pursue such mods. Hard to explain but if the mag box only needs to come forwards a few mm (say 120 thou), people to tend to back out of the project (wanting to keep the action somewhat original) and the whole situation kind of stagnates. It is only when people make a large mistake in judgement (eg .280 Rem, 7mm rem Mag, .300 Win Mag) that they are forced to make the decision to get stuck in and properly modify the Mauser. These are the type of realities I have to take into consideration when writing. What people ideally 'should' do versus what they actually do in certain situations such as this tend to differ. Regarding barrel length. Yes, a 26" barrel can be highly useful- but it pays to avoid anything to skinny as this will induce whip. If you have a smith copy the profile of an SPS magnum but with some barrel parallel rather than an immediate taper, you will be on the right track. Do not discount your M77 as others have stated. But by the same token, do not expect it to perform optimally without bedding and trigger work (and more- see books). The M77 rifles generally have a long throat and the mag length is more than adequate. These rifles will go 2900-2925fps with a 150gr bullet if approached following the steps others have outlined. Your 26" barreled theoretical rifle will go around 3000fps or so. But if you really want speed, keep in mind that it can be better to hop up to a magnum. Sometimes we try to trick ourselves by thinking that a smaller cartridge will recoil less (and have less wear) than a larger cartridge but we then try to load up to the speeds of the larger cartridge anyway. Having said this, the .270 Win firing a 150gr bullet at either 2900fps or 3000fps is potent. |
|
@ 10:22 pm (GMT) |
Richard WeidemannRe: Length of barrelThanks for all the replies and good info. Just FYI, the only reason I'm planning on rebarreling the Mauser is because the barrel is severely corroded from my neglect years ago. I'd shot corrosive surplus ammo through it and didn't "get around" to cleaning it out for a long time. The action still operates smoothly and, aside from some minor pitting just below the stock line that's been there since the day I got it, it's in good condition. I'd had it headspaced and test fired by a GS when I first got it, so I know the action is sound, which is why I believe that it's worth rebarreling. I also hate to see a perfectly good action just sitting in the safe, simply because it's attached to a now-crappy barrel.As far as the M77 goes, I'll be making a concerted effort to group it, probably this coming weekend, with factory ammo. |
|
@ 07:42 am (GMT) |
Richard WeidemannRe: Length of barrelWell, I went to the range today and have pics of the targets, but I can't figure out how to post them! Until I can, I'll say that the M77 shot fairly well, as did the M96 Swede in 6.5x55. My shooting form, however, needs improvement, as was reflected in the targets. Most of the groups were fairly good (roughly 1.5" for each), with fliers in each group. I don't have a rest, so today I shot off of a pack (taking a cue from Nathan), perched on a picnic bench. The setup (pack and bench) was stable, but I was not. And yes, Nathan, I was holding the fore end as you described in your article (it helped a lot, by the way) So, I'll be performing the test again and work on my shooting form.In the mean time, I'm waiting for all 4 of Nathan's books with baited breath. |
|
@ 06:21 am (GMT) |
Thomas KitchenRe: Length of barrelgreat to see an update, thank for keeping us informed Richard.enjoy the books Richard and please keep us updated |
Please wait
ABOUT USWe are a small, family run business, based out of Taranaki, New Zealand, who specialize in cartridge research and testing, and rifle accurizing.
|
KNOWLEDGEBASE |
KNOWLEDGEBASE |