Chamber dimensions allowed in F/TR?

L

LRCampos

New member
A friend asked me yesterday about two rifle he have, one is a .223rem with a .248 neck and other is a .308win with a match chamber (I suppose is about .337 neck).

He asked me if these two rifles with those chambers are LEGAL in F/TR. Are they?

The rules says about the cartridge, not the chamber. On my thinking, if a factory round enters the chamber, it is legal. If the factory round does not enter the chamber (without a neck turning), it is not legal. Am I right?


Here is what the rule says:

A rifle restricted to the chambers of unmodified .308 Winchester/7.62mm NATO or
unmodified .223 Remington/5/56mm x 45 NATO cartridge cases.
 
Get a Wilson chamber type case gauge. If the cartridge won't fully enter the case gauge then you have a problem. Otherwise, don't make it more difficult than it needs to be.
 
I may be wrong, but i understand this way...

Custom chambers are normally in the tight side.
If you do the test with the Wilson chamber type gauge, who I believe is in the SAAMI specs, almost any custom cartdrige will fit. If the intention is avoid ammunition with custom dimension,( and its advantages) then you have to test the rifle CHAMBER with ammunition within the SAAMI specs.
But, for security reasons, a dummy round may be the best alternative.

Those who know, please help. Newbies here;)
 
F Class TR Rules

Many of the F- Class rules are from the highpower rule book. FTR chambers are supposed to be SAAMI or CIP spec.
Nat Lambeth
 
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Again... don't make this harder than it has to be.

The intent is not to prohibit custom ammunition, or tight chambers, or anything of that sort. The point is to prevent some sort of improved/modified chamber (e.g. 'Ackley') that would allow extra boiler room and hence faster muzzle velocity i.e. a competitive advantage. Checking whether a dummy cartridge or plug of some sort will chamber in the gun is pointless, as the 'improved' chamber will most likely still swallow it with out problem. Checking a fired case from an improved chamber in a SAAMI spec case gauge will show very rapidly whether a competitor is using an 'unmodified' .308 Winchester or not.
 
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Liseo, I think it pretty much covers our doubts.

And the rifles I mentioned on the first post, are then, legal in F/TR. ;)
 
Simple solution. Range Master carries one each, Factory .223 and .308 cartridge and one each Milspec. 5.56X45 and 7.62X51. If they fit your chamber you shoot F/TR if not you shoot F/O or go home. No arguments aloud.

D R
 
How about a simpler solution - match director uses a case gauge for the reasons mentioned above and keeps his mitts off my gun and his ammunition of questionable lineage the heck out of my chamber?

What part of 'a standard cartridge will go into an Ackley Improved chamber' don't you people understand?
 
milanuk said:
How about a simpler solution - match director uses a case gauge for the reasons mentioned above and keeps his mitts off my gun and his ammunition of questionable lineage the heck out of my chamber?

What part of 'a standard cartridge will go into an Ackley Improved chamber' don't you people understand?
Click to expand...

Same part of a standard case gauge!

D R
 
Really. Every Ackley or 'improved' case I've seen has the shoulder blown forward and/or the body taper removed. Thats what gives it the additional case volume and extra velocity i.e. competitive edge. I don't see how it could go into a standard SAAMI case gauge - but it's pretty obvious how a standard cartridge would slip into an Ackley Improved chamber without a hiccup. People do exactly that all the time to fire-form Ackley cartridges.

I think some folks have the misconception that the 'unmodified' bit was meant to limit the accuracy to that of a factory chamber by insisting that people use a chamber that most brass rattles around in; again, I disagree. It's meant to limit someone trying to run a wild-cat chamber and get 'improved' velocity and an edge in the wind. Yes, it would be nice if the NRA rules were a little more specific on this point - but they aren't.

In actual practice, its been somewhat of a moot point up to this point. Most match directors are still conventional High Power shooters. They have enough other concerns on their time, and almost certainly aren't going to go out of their way to check each and every chamber in F/TR unless someone lodges a specific complaint against someone else. Should the match directors be ready in case of such a complaint? Probably. Don't count on it, though.

The recent FCNC in Butner had a small issue along these lines... someone had been grousing about someone else's chamber, so the match director put notice out there that chambers or fired brass may be checked. So far as I know, the chamber idea was dropped pretty quickly for the reasons I've detailed above. The final plan (so far as I heard) was the match officials would request a fired case from competitors if necessary, and the match official would select the fired case, not the competitor, and test it in a case gauge. I never heard if anyone got tested as such; generally that sort of 'cheating' is not an issue inside High Power Rifle in my experience. You can garner enough extra 'boiler room' by simply running thin Winchester brass in a sloppy SAAMI chamber and neck sizing only if thats what you're after.
 
Modified 308 chamber...

There was a rumor that a competitor was taking a 308 reamer and running in his barrel an extra .050" or so. Then making new brass with 8 x 57 or 3006 cases sized, trimmed and fireformed. The modified case would barely be noticable to the naked eye. The extra .050" case length would give about 5 more grains of capacity or about 10% advantage. This would be significant with 185-210 grain bullets in a 308 limited class. The Match Director for the F- Class Nationals got wind and nipped it in the bud, the possibility for anyone to cheat. Instead of catching the suspect they warned him along with everyone that a fired case and/or the chambers might be checked. To my knowledge the threat of checking cases and chambers kept the match legal. Sadley this issue needs to be continually addressed as the competition gets tighter and tighter. Over the years I have heard of a number of competitors that have tried to game the system. It is sad day when some one will resort to cheating to win at sport.

Nat Lambeth
 
Rustystud said:
There was a rumor that a competitor was taking a 308 reamer and running in his barrel an extra .050" or so.
Click to expand...

Exactly the sort of thing that would *not* be caught by inserting a cartridge or dummy round of any kind, but would show up pretty clearly with a case gauge... they'd stick out like a sore thumb.
 
And

One would simply need to look at the headstamp. If it says "30-06 Springfield" on it, that should be a pretty big tip-off that something is not quite kosher............jackie
 
European cases don't always identify the cartridge.

Jackie:

You are right but there are some exceptions. There are some European cartridge makers who don't head stamp cartridges.

Nat Lambeth
 
Rustystud said:
There was a rumor that a competitor was taking a 308 reamer and running in his barrel an extra .050" or so. Then making new brass with 8 x 57 or 3006 cases sized, trimmed and fireformed. The modified case would barely be noticable to the naked eye. The extra .050" case length would give about 5 more grains of capacity or about 10% advantage. This would be significant with 185-210 grain bullets in a 308 limited class. The Match Director for the F- Class Nationals got wind and nipped it in the bud, the possibility for anyone to cheat. Instead of catching the suspect they warned him along with everyone that a fired case and/or the chambers might be checked. To my knowledge the threat of checking cases and chambers kept the match legal. Sadley this issue needs to be continually addressed as the competition gets tighter and tighter. Over the years I have heard of a number of competitors that have tried to game the system. It is sad day when some one will resort to cheating to win at sport.

Nat Lambeth
Click to expand...
A modified reamer to set the shoulder forwards at the same OAL would allow use of fireformed cases with the proper .308 headstamp.
 
Using standard 308 case will work but...

Fireforming a standard 308 case would leave you with a short neck. It would be like converting a 6mmbr to a 6mmbrx. the short neck would be very noticeable. If you did this you would have to use a modified reamer with a shorter neck and throat length. There would be accuracy issues with having a short necked case. This is why we have reamers made for the 6mmBRX instead of just running the 6mmBR reamer deeper.

Checking the fired case in a case gauge is a tell all. Using a SAAMI/CIP spec go and no-go gauge will also tell all for the headspacing. These gauges measure off the datum point on the shoulder and the case head (true headspace. There is no measurement of the neck or throat. There is no chance of damage using these gauges. All properly made rifles have already had steel gauges in them.

A little unrelated but a bit rarely shared information about Insured Gunsmiths and Manufactures. Besides requiring a license (FFL). There are only two insurance underwriters in the United States. If you read their fine print, they require all chambers to be cut to SAAMI specs and SAAMI requires the use of both a Go and No Go Gauge made of steel. There is a reason for this they want to insure (no puns) the chamber falls witnin the maximum and minumum (.0035") specs. Properly used steel gauges don't lie.

Nat Lambeth
 
Maybe The Terms Are Confusing Some Shooters

I feel a little strange getting involved in a F-Class discussion, but I will throw this out.

When many hear the term "custom chamber', or "match chamber", they think of a chamber that will not accept a Factory Round, such as what many Benchrest Shooters use.

This is simply ingnorance of the terms used. I have a minimum spect 308 "match" reamer that will chamber any Factory round made. It simply produces a chamber on the bottom side of all the tolerances, such as body and neck diameter. I set it up with the same go-no go gage as is used in a standard reamer.

Not being a participant, I wonder just how epidemic this trend of 'stretching the rules" is in F-Class. It would seem so simple, either the chamber will accept a Factor Case, or it won't.

Maybe this is why 100-200 yard Benchrest would rather not get involved in so called "Factory Class" equipment..............jackie
 
jackie schmidt said:
Not being a participant, I wonder just how epidemic this trend of 'stretching the rules" is in F-Class.
Click to expand...

Jackie,

Being as there is little to no enforcement on the vaguely worded 'unmodified' .308 or .223 cartridge bit, it's impossible to say for sure.

Generally speaking, most people who choose to shoot F/TR do so specifically to get away from the whole 'arms race' of other disciplines (even F/Open). From what I've seen, the average F/TR shooter competes against themselves, the conditions, and their fellow shooters in pretty much that order. In that environment, the incentive for cheaters is pretty minimal.

Given that the HP community as a whole isn't *that* big, and the F/TR community is a small (but growing) slice of that... its not a group you want to garner a questionable reputation in.

Monte
 
F/TR (F class for Target Rifle derived equipment) carries a lot of baggage from the origin of the potential participants in the various countries.

  • Canada invented the game (probably) & has stayed largely true to the original rules, ie shooting off a bipod & bag with international Palma loadings (up to 155 grain loads for the .308, for example). It devised the discipline purely as a means that less robust or sighted shooters might adopt to stay in the sport.
  • Britain expected that it would attract the (1000, 11000 & 1200 yard) match rifle shooters who were considered to be the most able handloaders in their ranks - remember that TR at Bisley uses promoter issued ammunition. As MR shooters were versed in the benefits of heavy projectiles, Britain opted for an unlimited projectile weight, contrary to their TR limitations.
  • US Palma rules already had unlimited projectile weights, so that option was a no brainer Stateside. In addition, they specifically ruled against sophisticated rests etc, as the sport "is not belly benchrest", acknowledging that unique status you have where your shooting sports are commercially franchised. There may well have been a consideration to draw participation from the tactical shooters as well, whose rifles generally have barrels too short to handle the lighter projectiles as efficiently as a Palma .308 might.
  • Australia considered open & standard (F/TR) to be substantially similar disciplines, the difference being that the former have generous choice of equipment & calibre while the latter are restricted to the same maximum TR projectile weights as Canada but can use about the same range of rests. Thus the difference is that open shooters select a suitable calibre/load mix while standard shooters rely on the level of tuning they can achieve.
The issue of chamber dimensions probably came from Britain where until recently, the Radway Green military sniper ammunition that they used in competition was on the upper end of spec tolerances, resulting what we know as the "Bisley" chamber. However, it achieved a degree of US support where wildcatting is common. On the other side of the coin, I suspect that some of the popular .308 reamer specs might challenge the minimum standard specification of SAAMI or CIP.

But, as Monte says, at the end of the day, somebody is going to notice cases with bodybuilders' shoulders & necks to the permanent detriment of the user & those at the minimum end of tolerances shouldn't be of consequence (other than in countries where independent proofing is required).
 
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