Does anyone use a tight neck .308 chamber in F class. Will they go 60 rounds without a cleaning or will there be cambering problems? Is it even legal under the rule of "un modified case"? I see people using no neck turn chambers for Lapua brass at .342, but haven't seen a tight neck chambered rifle.
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F T/R Competition Tight neck for f class Ftr
- Thread starter AllenP
- Start date
Re: Tight neck for f class Ftr
Haven't seen anyone go down that path... thought about it, but given my current setup haven't had the need to try it. Given that we *do* shoot down on the deck, even if it is on a relatively flat/tidy KD range, stuff can and does still find its way into the chamber. A little clearance for crud isn't a bad thing...
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: AllenP</div><div class="ubbcode-body">Is it even legal under the rule of "un modified case"</div></div>
As far as 'unmodified' goes... think more in terms of 'not improved', i.e. a fired casing must still fit in a SAAMI case gauge such as the ones from Dillon or Wilson. A tighter chamber doesn't provide extra capacity, like an Ackley could.
Haven't seen anyone go down that path... thought about it, but given my current setup haven't had the need to try it. Given that we *do* shoot down on the deck, even if it is on a relatively flat/tidy KD range, stuff can and does still find its way into the chamber. A little clearance for crud isn't a bad thing...
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: AllenP</div><div class="ubbcode-body">Is it even legal under the rule of "un modified case"</div></div>
As far as 'unmodified' goes... think more in terms of 'not improved', i.e. a fired casing must still fit in a SAAMI case gauge such as the ones from Dillon or Wilson. A tighter chamber doesn't provide extra capacity, like an Ackley could.
Re: Tight neck for f class Ftr
I know of at least one shooter who ran a .331 neck in England, but he's most certainly in the minority. Lots of folks w/ .341 neck. An unturned lapua neck will give you a loaded diameter of about .337. Seems to work just fine.
I know of at least one shooter who ran a .331 neck in England, but he's most certainly in the minority. Lots of folks w/ .341 neck. An unturned lapua neck will give you a loaded diameter of about .337. Seems to work just fine.
Re: Tight neck for f class Ftr
I use a .339 in mine I've gone hundreds of rounds between cleanings and I've never had any trouble with Winchester or BHA brass (same, same) I've not tried Lapua yet.
I use a .339 in mine I've gone hundreds of rounds between cleanings and I've never had any trouble with Winchester or BHA brass (same, same) I've not tried Lapua yet.
Re: Tight neck for f class Ftr
The 308 Thompkins reamer runs a .343 neck and is extremely popular. .004-.006 clearance is the norm for most shooters.
The 308 Thompkins reamer runs a .343 neck and is extremely popular. .004-.006 clearance is the norm for most shooters.
Re: Tight neck for f class Ftr
I have a friend and my uncle run tight neck chambers on f-class rifles. One uses a .300 win mag and the other a .308 They have never had an issue with dirt or shooting several hundred rounds in a match. They are sticklers for up-most accuracy, and I have not been able to persuade them to not go tight neck. The only problem(s)is that you have to turn necks which sucks, and you can not run factory ammo if you screw up your reloads.
I have a friend and my uncle run tight neck chambers on f-class rifles. One uses a .300 win mag and the other a .308 They have never had an issue with dirt or shooting several hundred rounds in a match. They are sticklers for up-most accuracy, and I have not been able to persuade them to not go tight neck. The only problem(s)is that you have to turn necks which sucks, and you can not run factory ammo if you screw up your reloads.
Re: Tight neck for f class Ftr
I've been running a chamber that has a .340" neck. Taking just enough off the neck of Lapua brass for full clean-up the loaded round measures .337"~.3365". I haven't had any loading issues after firing 100 rounds+ through the barrel. I can chamber and fire factory ammo if I wish...
I've been running a chamber that has a .340" neck. Taking just enough off the neck of Lapua brass for full clean-up the loaded round measures .337"~.3365". I haven't had any loading issues after firing 100 rounds+ through the barrel. I can chamber and fire factory ammo if I wish...
Re: Tight neck for f class Ftr
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: XTR</div><div class="ubbcode-body">I use a .339 in mine I've gone hundreds of rounds between cleanings and I've never had any trouble with Winchester or BHA brass (same, same) I've not tried Lapua yet. </div></div>
WIN brass loaded rounds measure .334" OD versus the Lapua .337".
Running a one thousandths radius difference between the case OD and neck ID would be asking for trouble.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: XTR</div><div class="ubbcode-body">I use a .339 in mine I've gone hundreds of rounds between cleanings and I've never had any trouble with Winchester or BHA brass (same, same) I've not tried Lapua yet. </div></div>
WIN brass loaded rounds measure .334" OD versus the Lapua .337".
Running a one thousandths radius difference between the case OD and neck ID would be asking for trouble.
Re: Tight neck for f class Ftr
I question the value of the tight neck chamber. I know benchresters do it, but I know I've also read articles where folks have experienced poor accuracy that improved by increasing neck clearance a few thou. Seems to me like a chamber that doesnt allow the caseneck to get the f**k out of the way and just let the bullet launch would induce a lot of variability in "initial" internal ballistics.
Moreover, I KNOW better than 1/4 MOA accuracy can be achieved without neck turning and tight neck chambers, and wonder how many more points could be achieved in a match by increasing accuracy from even 1/4 MOA to 0 MOA...??
I question the value of the tight neck chamber. I know benchresters do it, but I know I've also read articles where folks have experienced poor accuracy that improved by increasing neck clearance a few thou. Seems to me like a chamber that doesnt allow the caseneck to get the f**k out of the way and just let the bullet launch would induce a lot of variability in "initial" internal ballistics.
Moreover, I KNOW better than 1/4 MOA accuracy can be achieved without neck turning and tight neck chambers, and wonder how many more points could be achieved in a match by increasing accuracy from even 1/4 MOA to 0 MOA...??
Re: Tight neck for f class Ftr
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: turbo54</div><div class="ubbcode-body">I question the value of the tight neck chamber. I know benchresters do it, but I know I've also read articles where folks have experienced poor accuracy that improved by increasing neck clearance a few thou. Seems to me like a chamber that doesnt allow the caseneck to get the f**k out of the way and just let the bullet launch would induce a lot of variability in "initial" internal ballistics.
</div></div>
IMO,
The main value is eliminating split necks while turning for neck concentricity.
Neck concentricity in itself (through neck turning) = more reliable neck tension, period.
Thinner neck walls in a spec. chamber allows the neck to expand and contract more, leading to faster cold working of the brass, leading to faster split necks.
Most BR guys shoot $1.00 (or more) per case chamberings, with modifications and fire-forming on top of that, plain and simple, alot of time and $ goes into the brass/ammo... Tight neck chambers (closer to resized demensions in general) just help to make one component last longer...
Granted, if your neck is TOO tight, you are lucky if bad accuracy is all you have to show for it.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: turbo54</div><div class="ubbcode-body">I question the value of the tight neck chamber. I know benchresters do it, but I know I've also read articles where folks have experienced poor accuracy that improved by increasing neck clearance a few thou. Seems to me like a chamber that doesnt allow the caseneck to get the f**k out of the way and just let the bullet launch would induce a lot of variability in "initial" internal ballistics.
</div></div>
IMO,
The main value is eliminating split necks while turning for neck concentricity.
Neck concentricity in itself (through neck turning) = more reliable neck tension, period.
Thinner neck walls in a spec. chamber allows the neck to expand and contract more, leading to faster cold working of the brass, leading to faster split necks.
Most BR guys shoot $1.00 (or more) per case chamberings, with modifications and fire-forming on top of that, plain and simple, alot of time and $ goes into the brass/ammo... Tight neck chambers (closer to resized demensions in general) just help to make one component last longer...
Granted, if your neck is TOO tight, you are lucky if bad accuracy is all you have to show for it.
Re: Tight neck for f class Ftr
Does this really help accuracy that much? Seems like a lot of work for minimal improvements on accuracy.
Does this really help accuracy that much? Seems like a lot of work for minimal improvements on accuracy.
Re: Tight neck for f class Ftr
If you are trying to beat world record groups it means all the difference, however if you are hitting steel, or even F-class targets not worth the trouble, and time. If you have tons of time, and all the stuff for it already I say go for it. Personally it would be hard for me to justify going tight neck in a f-class rig.
If you are trying to beat world record groups it means all the difference, however if you are hitting steel, or even F-class targets not worth the trouble, and time. If you have tons of time, and all the stuff for it already I say go for it. Personally it would be hard for me to justify going tight neck in a f-class rig.
Re: Tight neck for f class Ftr
Frank said it right... It depends on what you do and who you are.
Some people, myself included, enjoy reloading... I dont mind turning necks, fire-forming, annealing or uniforming flash holes. Ofcourse, I try not to loose focus on where true gains are to be made, actualy shooting!
Frank said it right... It depends on what you do and who you are.
Some people, myself included, enjoy reloading... I dont mind turning necks, fire-forming, annealing or uniforming flash holes. Ofcourse, I try not to loose focus on where true gains are to be made, actualy shooting!
Re: Tight neck for f class Ftr
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: turbo54</div><div class="ubbcode-body">Moreover, I KNOW better than 1/4 MOA accuracy can be achieved without neck turning and tight neck chambers...</div></div>
Tell ya what, I run the Benchrest program at Harrison Sportsmans Club. I'll send you the dates for our matches next year, wou bring up the rifle with the no-turn neck that shoots better than 1/4MOA. I'll pay your match fees AND your gas bill IF said rifle shoots a .250" agg. I'll throw in $50 if this magic rifle shots an agg of .220" or under. It will be a 100 yard group match, 5 shots per target, 5 matches per agg. Targets WILL be measured with an official scoring device, not the "measure the outside spread and then subtract one bullet diameter routine" (which gives you a .02"+ advantage).
If you'd prefer to shoot longer ranges let me know, it can be arranged....
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: turbo54</div><div class="ubbcode-body">Moreover, I KNOW better than 1/4 MOA accuracy can be achieved without neck turning and tight neck chambers...</div></div>
Tell ya what, I run the Benchrest program at Harrison Sportsmans Club. I'll send you the dates for our matches next year, wou bring up the rifle with the no-turn neck that shoots better than 1/4MOA. I'll pay your match fees AND your gas bill IF said rifle shoots a .250" agg. I'll throw in $50 if this magic rifle shots an agg of .220" or under. It will be a 100 yard group match, 5 shots per target, 5 matches per agg. Targets WILL be measured with an official scoring device, not the "measure the outside spread and then subtract one bullet diameter routine" (which gives you a .02"+ advantage).
If you'd prefer to shoot longer ranges let me know, it can be arranged....
Re: Tight neck for f class Ftr
That sounds like a challenge! I'm in. Sounds like fun. Can I fire prone? Don't care much for the bench.
SAC built 308 1:11.25 26" Bartlein
Once or twice or three times fired Lapua brass - zero case prep
43.2 gr Varget/175smk @ 2725fps
Loaded on dillon 650 ( charges weighed)
That sounds like a challenge! I'm in. Sounds like fun. Can I fire prone? Don't care much for the bench.
SAC built 308 1:11.25 26" Bartlein
Once or twice or three times fired Lapua brass - zero case prep
43.2 gr Varget/175smk @ 2725fps
Loaded on dillon 650 ( charges weighed)
Re: Tight neck for f class Ftr
Yep, we've got a couple of target frames at the end of the line that doesn't have benches...
Yep, we've got a couple of target frames at the end of the line that doesn't have benches...
Re: Tight neck for f class Ftr
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Wheres-Waldo</div><div class="ubbcode-body">Please God let this happen... I need some legitimate SH drama! </div></div>
I can't back down from a shooting challenge. I have been put in my place before and it'll sure happen again, but if 5 five shot ~40 cal holes can compete, I think I can hold my own. Plus, I don't mind losing - that badly...
Is this already on the schedule? I'll easily forget so I need to add it to my calendar or ask for a reminder.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Wheres-Waldo</div><div class="ubbcode-body">Please God let this happen... I need some legitimate SH drama! </div></div>
I can't back down from a shooting challenge. I have been put in my place before and it'll sure happen again, but if 5 five shot ~40 cal holes can compete, I think I can hold my own. Plus, I don't mind losing - that badly...
Is this already on the schedule? I'll easily forget so I need to add it to my calendar or ask for a reminder.
Re: Tight neck for f class Ftr
I've got to turn the dates to the club. I'll let you know as soon as their published.
It would be fantastic to see a .308 shoot those kind of groups. We've been down that road on this site before with people posting photos of groups supposedly that small. Most of those groups ran in the low .3's which is outstanding, IIRC only one group aproaching 1/4MOA
Match would be 5-5 shot groups for an average of .250" at 100 yards. Matches are 7 minutes long, unlimited sighters and five shots for record. Normally there's a 25 minute break between matches.
If the average is bigger than .250" you can buy me a hamberger after the match...
I've got to turn the dates to the club. I'll let you know as soon as their published.
It would be fantastic to see a .308 shoot those kind of groups. We've been down that road on this site before with people posting photos of groups supposedly that small. Most of those groups ran in the low .3's which is outstanding, IIRC only one group aproaching 1/4MOA
Match would be 5-5 shot groups for an average of .250" at 100 yards. Matches are 7 minutes long, unlimited sighters and five shots for record. Normally there's a 25 minute break between matches.
If the average is bigger than .250" you can buy me a hamberger after the match...
Re: Tight neck for f class Ftr
As I said above, I have not tried Lapua brass yet in my rifle, at .339 it feeds Winchester every time. I do not turn necks, I do use a Lee collet instead of a bushing in an effort to achieve consistent neck tension.
As I said above, I have not tried Lapua brass yet in my rifle, at .339 it feeds Winchester every time. I do not turn necks, I do use a Lee collet instead of a bushing in an effort to achieve consistent neck tension.
Re: Tight neck for f class Ftr
Howdy Gents,
I was discussing this very topic not to long ago. I still have not reached a conclusion. My fired Winchester brass measure .332. I had my full length Forrester dies in to be honed to .331 well they honed them to .332 so now I use a bushing neck sizer .330 and my chamber is .342 neck. Is .012 too much? I don't turn the brass but wonder if I am going to split it. I have culled one because of a bad spot but can't say its a crack.
PO-PO
Howdy Gents,
I was discussing this very topic not to long ago. I still have not reached a conclusion. My fired Winchester brass measure .332. I had my full length Forrester dies in to be honed to .331 well they honed them to .332 so now I use a bushing neck sizer .330 and my chamber is .342 neck. Is .012 too much? I don't turn the brass but wonder if I am going to split it. I have culled one because of a bad spot but can't say its a crack.
PO-PO
Re: Tight neck for f class Ftr
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: AJ300MAG</div><div class="ubbcode-body">I've got to turn the dates to the club. I'll let you know as soon as their published. </div></div>
Tag for later
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: AJ300MAG</div><div class="ubbcode-body">I've got to turn the dates to the club. I'll let you know as soon as their published. </div></div>
Tag for later
Re: Tight neck for f class Ftr
somebody wanna fly me in from NY , I got a box stock savage 10 that I can do that with. , using mil brass and absolutely no attention to the necks , hell I couldn't even give you the size I run them at.
I have group pics how do i post them ?
somebody wanna fly me in from NY , I got a box stock savage 10 that I can do that with. , using mil brass and absolutely no attention to the necks , hell I couldn't even give you the size I run them at.
I have group pics how do i post them ?
Re: Tight neck for f class Ftr
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: fmelloni82</div><div class="ubbcode-body">somebody wanna fly me in from NY , I got a box stock savage 10 that I can do that with. , using mil brass and absolutely no attention to the necks , hell I couldn't even give you the size I run them at.
I have group pics how do i post them ? </div></div>
Anyway, I sent the reamer back to have it ground to .340. Thanks for the input everyone.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: fmelloni82</div><div class="ubbcode-body">somebody wanna fly me in from NY , I got a box stock savage 10 that I can do that with. , using mil brass and absolutely no attention to the necks , hell I couldn't even give you the size I run them at.
I have group pics how do i post them ? </div></div>
Anyway, I sent the reamer back to have it ground to .340. Thanks for the input everyone.
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