6.5 Grendel barrel Length?????

[ricsmall]

I found them, They are some great reads about the capability of a sbr grendel. I love it

I love it as well!! I read some more and decided to get a psa upper to quench my thirst until the group buy barrels get here. I have a feeling by then I will have decided to build another for my son. That means another F1 can. Busy busy. Can’t wait to try it out.

[NugginFutz]

lazyengineer...only problem with 1000fpe at 300yds is you 800fpe below the threshold bullet manufacturer design their bullets.

CC - lazyengineer was talking Foot Pounds of Energy at those distances. The manufacturers are talking Feet Per Second when setting their minimum expansion criteria, not energy. The Grendel doesn't make 1800 FPE at the Muzzle, let alone at 300 yards.

Your not going to get that by burning the bulk of your powder charge in the air outside the muzzle. If your velocity is all over the map you will string your shots vertically and the BC of your bullet changes as the slows down. So some shots will drift more than other with the exact same hold!

I'm also curious where you get the idea that the 12" barrels are burning most of the powder beyond the muzzle. Would you mind please citing your source for this claim?

[CaptnC]

NugginFutz,

Let me ask you a question...would you use a slow powder in a short barrel? Most of the common powders are middle toward the slow end of powder burn rate charts.

Pistols use fast burning powders...WHY? Because they have short barrels and to get the most out of your powder charge, you want the last few grains at or near the muzzle.

I hunt out of trucks, blind and stalking through the woods all the time with 26" barrels. It's never cost me a shot nor given any reason to break out a saw to cut it in half.

As a mater of fact, UPS is delivering me a new 26" 6.5x284 varmint contour barrel tomorrow!

[ricsmall]

CaptC

Think about all those savage stryker and rem XP100 Pistol’s that have been built and shot over the years. They’ve been chambered in .223,.308,30-30, 30 herrett to name a few. They work. They work with equal or greater powder charges than the Grendel. No one is claiming a 12” barrel Grendel is the ideal choice for 1200yd shooting. It is however a good choice for medium game up to ~300 yds or so. The powder isn’t burning all the way to the end of barrel in most cases. The burning rate determines the rate of detonation which determines the pressure curve which determines the velocity and peak pressure. Short barrels work in rifle cartridges, they have for years. Ideal for every situation? No. Is there any gun ideal for every situation? No. I’m not carrying my 26” 260AI to shoot a deer at 80-300 yds. I’ve killed a truckload of deer with .223 from 30-340 yds. Ideal? No. Look up on you tube, or on the LRH forum. Guy shooting an.375 cheytac pistol at 1500 yds IIRC. I’m works. No need for all the arguing. Different strokes for different folks. I will report back on my 12” build after completed.

[HickLife]

Why does every forum have to have someone that thinks their way is the only way and if you do or think differently then you are an idiot and in this case have no balls?

CaptC,

I'm not an expert, and have seen arguments both ways about powder being burnt in the first 6" of the barrel or the full length (or outside if too short), but if wasting unburnt powder and potential was a concern then why not use a faster burn rate powder and a smaller charge so you use it up? There are things to do to make up for that, and for some it just isn't a concern. If I know I won't take a shot outside of 300yrds, and I know that my 12" rifle will be able to take that shot and take down whatever animal, I am hunting I'm going to take that and not my 24". If you want to lug around a long rifle go ahead but i'm not getting any added benefit from it if I'm taking a relatively short shot. The bullet will still expand, if I have a good barrel it will be just as (if not more) accurate, and the animal will be just as dead. But if you want to lug around a 26" rifle go ahead, I'm not going to stop you.

I also noticed that the link was to a long range hunting forum. In the thread you were saying we are all idiots and you don't understand our logic. With long range hunting I understand the need to get everything out of the round, but if you are that concerned with the ballistics and potentially wounding and not killing an animal at those long ranges wouldn't you go with a different larger caliber? Maybe a 308, creedmore, or even a win mag. Better stick with a bolt gun also, because you are leaving accuracy on the table if you don't. Nothing less than a 26" bull barrel either.

[CaptnC]

ricsmall...FINIALLY! I've been won drink why no one remembered that group. We have a bunch of guys on LRH Forum who shoot those platforms...so I have been waiting...just don't have the time for the full reply. But it's comung!

[bj139]

I remember years ago shooting magnum pistols. Win 296 powder produced the highest velocity at safe pressure but unburnt powder could be almost dumped out of the pistol after each shot. It is what it is.

[CaptnC]

HickLife,

Why?
Because the OP is normally ask what is the best barrel length.

Why would I tell someone the best barrel length is 12.5 when it's not true.

18 to 20 is best, but if you want to reat maximum benifit from a Grendel go to 24".

I assume you have not read all my posts on the subject

I agree...if you use a shorter barrel, the most commonly used powders in a Grendel are not the best choices.

I still don't have time to fully reply, but I was just thinking last night when I posted..."I can't believe no one has called me on the bolt action pistols"....

I will find the time...

[Bigs28]

I don't see where he asked "best" barrel length. He asked for barrel length for hunting small to medium sized game with no shots over 300 yards. Your "opinion" that an 18"-20" barrel is best is relative to what your looking for. It is not the "best" for me and my wants/needs.

I personally don't see how a 20" is best at anything. It's in the middle. Kinda average of everything.

[Mad Charlie]

I remember years ago shooting magnum pistols. Win 296 powder produced the highest velocity at safe pressure but unburnt powder could be almost dumped out of the pistol after each shot. It is what it is.

And regardless of barrel length! I still do that. Powder that gives the highest velocity in a 6" bbl gives the highest velocity in a 2 1/2 bbl.

[NugginFutz]

NugginFutz,

Let me ask you a question...would you use a slow powder in a short barrel? Most of the common powders are middle toward the slow end of powder burn rate charts.

Pistols use fast burning powders...WHY? Because they have short barrels and to get the most out of your powder charge, you want the last few grains at or near the muzzle.

I hunt out of trucks, blind and stalking through the woods all the time with 26" barrels. It's never cost me a shot nor given any reason to break out a saw to cut it in half.

As a mater of fact, UPS is delivering me a new 26" 6.5x284 varmint contour barrel tomorrow!

Interesting - you clearly illustrate your preferences for longer barrels, and trot out some anecdotes from your personal experience.

Yet, I am still waiting for your citation which backs up your claim that a 12 in. barrel is "burning the bulk of your powder charge in the air outside the muzzle."

I understand you have an opinion to which you are entitled. I do not agree, however, that you can float that opinion as fact without the supporting data.

[LRRPF52]

Do you mind providing a link to that I would like to look at it

http://www.65grendel.com/forum/showthread.php?16587-Update-12-quot-Faxon-Group-Buy-Barrel-Shorty-now-w-suppressed-results

[LRRPF52]

Powder conversion with most of the propellants we use in 6.5 Grendel is almost 100% complete within the first 1.5-3" usually, depending on the propellant/projectile combo.

"Unburnt" gets confused with "mostly-converted" powder that has already been burned and released its potential energy within the first few inches of the chamber, but leaves tiny residual particulates that are still very hot. We also get soot residue inside the spent case, which reloaders are generally familiar with.

If considerable unburnt powder was making it to the gas port, imagine what would be happening in your gas system.

Pressure and heat are greatest at peak chamber pressure, which is when the projectile has barely moved. Some adhere to the static projectile argument with it retained by the neck still, while the Army Research Lab shows primer-induced projectile jump into the lands, but still in contact with the neck.

Either way, those places are where the powder conversion happens. The potential chemical energy of the propellant compound is converted into an energetic gas wave when the primer detonates and ignites it, which continues to propagate for tiny fractions of a second after powder conversion. This is why barrel length adds velocity relative to the time the wave dwells in the bore up until a point where it doesn't, which is dependent on propellant volume, bore volume, propellant burn rate, projectile weight, and other factors. Even in the case of long barrels or insufficient propellant, the inertia imparted to the bullet is enough to get it to exit, with the rare cases of squibs where only the primer or unusually low propellant volume was detonated, leaving the projectile in the barrel.

This is why we have tested load data for specific rifle cartridges and projectile weights, because some powders don't convert well at all for the bore volume and projectile weight, and some convert too fast to the point of exceeding peak pressure set by SAAMI. For example, you wouldn't use really slow-burning propellants in 6.5 Grendel, like the kinds we use in large case volume magnums with larger bores.

The flash you see at the muzzle is the result of the converted gas wave once it hits open atmosphere with more oxygen present to feed the exiting hot gas, not unburnt powder continuing the conversion process. You will often have small particulate matter exiting the muzzle left over from the process, as well as jacket material from the bullet. At night, you will normally see sparks along with muzzle flash from a lot of guns. The residual particulate matter from the propellant is still extremely hot, so when you do see fiery little specs from short barrels at night, that's what you are witnessing.

To have unburnt powder flowing into your gas system would be really bad.

I would also point out that if you're on a phone, it may create the typo, "handy capping" when someone is trying to say, "handicap".

Of course, "handy capping" could be a serendipitous happy accident that gains traction as a convenient way of executing suckahs in the ghetto with a G-Lock fo-tay.

[LRRPF52]

As to the practicality of short barrels in 6.5 Grendel, it helps to look at .30-30 Winchester performance as a commonly-known and accepted hunting cartridge that is responsible for a lot of dead dear over the last 124 years and compare them within common hunting distances.

An 11.5" or 12" Grendel will have more energy at 400yds than a 20" barrel .30-30 Winchester has at 200yds, and excellent penetration, expansion, and weight retention with common hunting bullets.

It has plenty of killing power within 200yds, easily exceeding the longer barreled AK and SKS shooting the exact same bullet weights.

[grayfox]

I'm looking at putting a 6.5 Grendel together for deer/pig hunting here in Missouri and a few southern states and was wondering what is the optimal barrel length. No shots past 300yards. I do shoot suppressed at times. 1-6X28 is my scope of choice due to close shooting done here in Missouri. I welcome all the hunters suggestions. Thank you, Jerry....

Here is the OP. He does not ask for the "best" but does ask about "optimal". Either way, both terms are judgment calls. As for the Ky long-rifle guys, you need 30" or better and Hawken 54 cal at least... Anyway, '52's (and others) answer that anything from 12-18" will suit the OP, keeping in mind his other reqts he added, 1-6x28 scope, 300 yds or less, suppressor et al... gives him plenty of room to make his own assessment. Maybe he wants the 20" or 26"... maybe he wants the 12 (or in my case the 12.5) b/c with suppressed it is just sweet to carry around.

Heck Op build 2! a 12-12.5 and a 16-20 (again your choice). Double your pleasure, double your fun. Nobody said you can only have 1.

I've owned and shot a 30-30 as I'm sure many on here have. And the Grrr is just must nicer to aim, shoot and watch your bullseyes -- better distance handling too....

CaptC if you want to stick with the 26" er's that's fine with me, should leave more Grendel stuff on the shelf for when I want it. But I don't really care either way.