Difference in standard and match chambers

[scooterf79]

Wanting to build a 280AI, pretty sure Im going to go with a criterion barrel. They have 280AI and 280AI Match chambers. Is there an advantage to one or the other. If so could you explain the difference to me.
Thanks
Scooter

[scope eye]

With the match chamber you are going to have to neck turn, and really pay attention to your brass and make sure every thing is just right or you will have problems chambering, they can some times be finicky, match basically means tighter clearances.

Dean

[82boy]

Any Time I see the words "Match," "Target," or "Benchrest," it raises suspicion. The first thing I ask is who determined that it was such a thing. These words are buzz words and strike up emotion, and are basically a marketing ploy. With that said just because them words are used doesn't mean that they produce a more accurate product, or that this is what Match, or Benchrest shooters use.

Now moving onto the question about the reamer, only the manufactory can truly tell you the difference. Most time companies use the term to set the product aside because they have made 1 or many revisions from the norm, or SAAMI guidelines. If they give you the "This is what Benchrest shooters or match shooters use," or "We used tighter standards." take it with a gain of salt, and you might be better off hanging up the phone. If the company is honest they will tell you why they have labeled it, and what the difference are. Most of the ones I have seen is that they made the throat longer for heavier VLD bullets, and the rest of the print is to SAAMI guidelines. So to answer your question call CBI or Jim Briggs and ask them what the difference is, they are the only ones that truly can.

[RP12]

All my rifle have "match" chambers. All my ammo "matches" my chambers.

[scooterf79]

RP12....nice! Lol

[scooterf79]

82boy, thanks for the info, Ive called cbi, theyre supposed to get back with me tomorrow....hopefully they can tell me their reasons. Im just wanting to see what your alls thoughts were on the differences.
Thanks
Scooter

[AZ_GUN_NUT]

All my rifle have "match" chambers. All my ammo "matches" my chambers.

exactly!

[northlander]

As Pat (82boy) has already stated, the main difference between the standard chamber and the Match chamber is the freebore. The "Match" chamber on the 280 AI has a .170 freebore where the standard SAAMI chamber has the minimum freebore. If you are looking to shoot the longer heavier bullets in your 280 AI you will want the 280 AI Match chamber.

The Criterion Match chambers are not tight neck chambers. The main reason that Criterion uses the term Match is to show the shooters and rifle builders that these chambers are not a standard chamber. Actually, most Criterion chambers that are marked as Match are normally chambers with a longer freebore. The exception to this rule is the Match Chamber that they use on the 204 Ruger and the 6.5X55 Swede calibers. In both of these calibers the Match Chamber actually has a shorter (modified) freebore to make that caliber shoot better. Both of these calibers were shortened to allow the shooters to have a chance of getting anywhere near the rifling with their bullets.

Questions pertaining to Criterion barrels are our specialty. If I can be of assistance please ask.

Jim Briggs
NSS

[Apache]

As a general rule, it's just hype. But some "match reamers" are truly setup for match shooting. The main area is (which has been mentioned) is the neck area of the cartridge.

There are some reamers that have been setup for a special freebore lengths (also mentioned)

But one area that few ever look at is the freebore DIAMETER. IMHO the MOST important dimension of all.

For example:

If the bullet diameter is exactly .308 then a freebore of .310 allows the bullet to move side to side before it engages the rifling. It is possible for the bullet to enter the rifling at an angle instead of parallel to the bore. This would induce unwanted bullet yaw even while the bullet is still in the barrel. It would get even worse once it clears the muzzle.

Most modern reamers are cut with a .0005 clearance on bullet diameter. In other words a proper freebore for the .308 caliber that is setup for accuracy minded folks is AT MOST .3085......3083 would be even better.

Check out the SAAMI specs on a 308 or 30-06 reamer and you will see what I'm talking about. They are set for .310..... Then check out the specs on what is called a 1995 308 Palma reamer. Or the 30-06 Serengeti reamer which are setup with special throated/freebore dimensions to help keep the bullet straight as it enters the rifling. You will find they have a tighter diameter freebore.

SAAMI spec reamers are terrible for the most part.......depending of coarse what those specs are.

Tighter freebore reamers are the way to go for accuracy.

[SFLEFTY]

Thanks to all of you for those answers. Good stuff here.

[scope eye]

Thanks to all of you for those answers. Good stuff here.

And a lot of Horse Hockey.LOL

Dean

[scooterf79]

Thanks guys for the replies...I appreciate the input, called Jim today and placed my order, went with the 280 ai match criterion barrel, and ordered my barrel nut and recoil from him as well. Thanks for the help Jim! Now Im gonna be like a little kid waiting for a new toy to come in :)