Range Report How to tell if a/your barrel likes certain ammo?

[ColtJ]

Hey,

Obviously when barrel and ammo are compatible tight groups and extreme accuracy are possible under the right conditions.

On the other side, what happens exactly if your barrel does not like certain ammo? Are there certain characteristics to look out for? Is it something that would even be repeatable on different barrels (to use as/for comparision) or is it just not accurate.

Also what are the odds of having inconsistent ammo from a major brand or are they (barrel and ammo) just not compatible? Poi varying in inches every now and then even when aiming at the same spot. IE: Large variances of POI at 50 yards where it shouldnt be as noticable.

Thanks.

 

[winxp_man]

Re: How to tell if a/your barrel likes certain ammo?

My first 6.8 SPC AR upper shot MOA or better with the Hornady factory rounds with no issues at all. I know got a new upper from WOA with a Shilen math barrel and it does not shoot the Hornady factory ammo well at all. I put my reloads through it and sub moa all day long. It's pretty simple of the ammo is not consistent from box to box then that amm will be no good for you. My .308 loves the factory 168 FGMM stuff but does not like the 175 FGMM at all. Another good thing to keep in mind is lot numbers. If you can check lot numbers when buying a few boxes of ammo that will also keep you shooting consistent. My 2 $'s

Aron-

 

[Jerry m]

Re: How to tell if a/your barrel likes certain ammo?

Shoot - group size will answer your question.

 

[ColtJ]

Re: How to tell if a/your barrel likes certain ammo?

Thanks guys,

Above confirms my concerns.

But may I ask why some barrel's like some ammo and others do not? I don't have a good grasp on this yet.

 

[damoncali]

Re: How to tell if a/your barrel likes certain ammo?

Nobody knows. I'm a firm believer that there is less of that going on than we tend to think, and that most of the "liking" and "not liking" is really just due to random noise.

In other words, if you take two identical barrels (same length, contour, material, chamber, etc) and put them on the same rifle, and use the same ammunition, you will burn out the barrels before you can tell a difference. I know many don't believe this, but to say that some barrels "like" different bullets in the absence of explanation is not far from magic.

That said, subtle changes can make a difference that is hard to nail down. I think arguments over leade angle fall into this category, for example.

 

[Gravity_Knight]

Re: How to tell if a/your barrel likes certain ammo?

I've been trying different ammo with my SPS tact 308. Few different brands until I started shooting Hornady.. their Superformance shoots noticeably flatter with tighter groups than anything I had tried so I stuck with their stuff. Now I'm trying to find the perfect grain bullet. So far I haven't found a particular grain bullet that my gun seems to "like" better than another. Could be my own fault though.. I am pretty accurate out to 500 yards.. at 600 my groups are probably 8-10"... I can't really tell if it's the ammo, or just me being a shaky SOB, wind, etc.

My $.02 worth of advice would be to try some different ammos/weights and check them at different distances. And then shoot the cheapest stuff that still performs for you. I am no expert however.

 

[ColtJ]

Re: How to tell if a/your barrel likes certain ammo?

I'll explain what I am experiencing. This may help you guys understand my question in a clearer light or at least relate to it.

Shot some 75gr BHTP match ammo and achieved a 5 shot group of .7 MOA, followed by 3 shots that would have yielded an even better group then the next two rounds fly left a whole inch. As I went through the box, the trend continued.

Luckily I had another box of ammo, some 60gr V-Max ammo and I was able to maintain groups around 1 MOA.

Then I went back to the 75 gr and got the same results.

Although the 60gr V-Max did not make a better group it was consistent, while the 75gr BHTP had a flash of brilliance it was not consistent at all (almost as if i was mixing ammo).

This is what got me wondering if this is a situation of having a barrel not like a certain type of ammo.

 

[damoncali]

Re: How to tell if a/your barrel likes certain ammo?

Be careful - you may just be witnessing the normal variation in group size and assuming that the oddball shots are "flyers" (in other words, the small group might just have been due to luck). A couple of 5 shot groups is just not enough data to draw any firm conclusions on how accurate a rifle/load combo is.

This is one of my favorites on the subject:

http://www.border-barrels.com/articles/rimfire_accuracy/group_statistics.htm

Long story short, you want to shoot 7 shot groups, not 5. And you need several of them to get anything resembling confidence in the results.

Unfortunately, that sort of testing can get expensive.

 

[tullius]

Re: How to tell if a/your barrel likes certain ammo?

This is just an issue of marksmanship, Colt, the ammunition is your red herring/chimera. If you shot one good group with 75gr BTHP, there's no reason you can't do it again once you figure out what you're doing correctly, and repeat it.

USAMU conducts the Rifle SAFS and associated EIC Match with stock Hornady 75gr. BTHP Match and rack grade M16A2's that rattle like a bucket of nuts(party switch blocked off). Every year, there are some pretty damn good scores posted with that standard equip.

In other words, don't get distracted by the pills or barrel specs, it's your technique. And you can fix that.

 

[ColtJ]

Re: How to tell if a/your barrel likes certain ammo?

Thanks for the reply's.

I have some black hills 77gr SMK to test this week. The results of this outing should answer a few questions, hopefully.

IE: whether its marksmanship or ammo, etc...