Savage 12FV owners, what length is your chamber before hitting the lands?

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RussellC

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Perhaps this should be "length of your bullet" but here goes. ( i have also posted a similar, but more geared to handloading in the handloading forum.) In the handloading forum, I am inquiring as to preferred COL measurements and anomalies with my hand loads , here the question is more specific to the physical attributes of the guns chamber.

BTW, my gun is in .223 Remington and this is my first bolt long gun.

Question: What sort of ammo are you using in your 12FV, and have you noticed bullets hitting the rifling? I am thinking this is based a somewhat short chamber in this gun?

Anyone measured chamber length on this gun? I have a RCBS precision micrometer (which I like) and it came with a little fake adjustable "bullet" to do this, but that thing is useless. Maybe someone has measured a factory round then chambered a round and then re measured? Or noticed high pressure signs on otherwise high quality ammo?

Anyone actually measured the chamber, etc? This sort of info would be valuable to me in getting this gun prepared to shoot. I am noticing some anomalies to my handloaded rounds, but that is addressed in the handloading thread.

Any help much appreciated,

Russellc
 
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Every chamber in every rifle is slightly different. Has to do with tools wearing. Chamber dimensions are set by SAAMI(Sporting Arms and Ammunition Manufacturers' Institute) with tolerances.
The bullet length is not what you're asking about. You're asking about the OAL of a loaded cartridge. If the cartridge is loaded too long you'll stick the bullet(the projectile) into the rifling and that can push the bullet into the case. Sometimes the bullet will be so far in that it will stay there upon extraction get pulled out and cause powder to be dumped into the rifle's action. Been there myself. Fixed by shortening the OAL. Seat the bullet a tick deeper.
The whole off-the-lands thing is a load tweaking technique that isn't absolutely necessary. Isn't done until you have worked up the load.
 
Thanks. I didnt mean to tweak it, this is a load out of Sierras file on AR15 loads. The 52or 53 grain HP (Match King) was 2.250, and the 69 grain Match King was 2.260. Both shoot fine in my ARs.

I will look at their "regular" rifle loads to see if they are set a little deeper in the case.

They didnt pull apart during extraction, but it was a little tougher than usual pulling the bolt back.

Russellc
 
Mine has a very short leade. Some bullets can't be loaded to book length w/o jamming into the lands.

I'm not sure how to quantify it. I have one of the Hornady measuring dohickeys where you put a bullet in the special case and measure how far the bullet goes out before hitting the lands. I could give you the measurements for the bullets I have on hand, which are 77SMK, 69SMK, and 60VMax.

I thought about getting it reamed to a longer leade, but then decided I'd just shoot it out and then get a better barrel :)

(ETA: while I'm happy to give you my dimensions, I'm not sure what good they would do - what you need is your dimensions. One of those Hornady widgets will let you get that:
https://www.hornady.com/reloading/p...on-tools-and-gauges/oal-gauges-modified-cases
 
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My maximum OAL for a Savage axis 223 is 2.300" any longer and there are feeding problems from the magazine.. The 69 gr Sierras (2) do not contact the rifling.
 
Pintler and Sunray have it spot on. If one has an extra case it can be split down the neck and used with an averaged, measured, bullet. Current to the lot that one is using. A very small cutoff wheel, such as a Dremel wheel, can cut down the length of the neck, allowing setback of the bullet upon contact of the leads. This can be measured, very carfully and several times, for contact to rifling. It helps to have a crush(gently) fit case and the ejector and extractor removed. If one knows this number it is and easy thing to adjust, even factory, ammunition.

I would use a case that matches all of the other cases that I use so that I can use the case head to bullet ogive measurement. The modified cases that Hornady makes may or may not be close to what one is producing in their regimen. I use the Hornady ogive measurement anvil that attaches to the caliper jaws. Though, even this number will be relative to only your chamber and measurement device.
 
pintler said:
Mine has a very short leade. Some bullets can't be loaded to book length w/o jamming into the lands.

I'm not sure how to quantify it. I have one of the Hornady measuring dohickeys where you put a bullet in the special case and measure how far the bullet goes out before hitting the lands. I could give you the measurements for the bullets I have on hand, which are 77SMK, 69SMK, and 60VMax.

I thought about getting it reamed to a longer leade, but then decided I'd just shoot it out and then get a better barrel :)

(ETA: while I'm happy to give you my dimensions, I'm not sure what good they would do - what you need is your dimensions. One of those Hornady widgets will let you get that:
https://www.hornady.com/reloading/p...on-tools-and-gauges/oal-gauges-modified-cases
Click to expand...
Ive got so many gauges and measurement devices I probably have the one you mention.

What might be helpful is your Sierra 69 grain match king load, including the OAL you use for your gun. Previously, I used 2.260 for the 69 grain and 2.250 for the 52 and 53 grain MK. Obviously, those lengths do not work. What is the longest OAL you can get away with?

Thanks, Russellc
 
243winxb said:
My maximum OAL for a Savage axis 223 is 2.300" any longer and there are feeding problems from the magazine.. The 69 gr Sierras (2) do not contact the rifling.
Click to expand...

Ok, the 69 grain SMK is one bullet I like to use, do you mean 2.300" or 2.230"? If 2.300, something may need reamed in my chamber. If 2.230, then I need to shorten my 69 grain loads to 2.230...

Russellc
 
Demi-human said:
Pintler and Sunray have it spot on. If one has an extra case it can be split down the neck and used with an averaged, measured, bullet. Current to the lot that one is using. A very small cutoff wheel, such as a Dremel wheel, can cut down the length of the neck, allowing setback of the bullet upon contact of the leads. This can be measured, very carfully and several times, for contact to rifling. It helps to have a crush(gently) fit case and the ejector and extractor removed. If one knows this number it is and easy thing to adjust, even factory, ammunition.

I would use a case that matches all of the other cases that I use so that I can use the case head to bullet ogive measurement. The modified cases that Hornady makes may or may not be close to what one is producing in their regimen. I use the Hornady ogive measurement anvil that attaches to the caliper jaws. Though, even this number will be relative to only your chamber and measurement device.
Click to expand...

Wondering how one adjusts factory ammo? I didnt quite follow that part...

Russellc
 
Unless you measure the actual chamber of your rifle,you will never know where the bullet touches the lands for any bullet that you want to shoot. I seriously doubt that you will have any problems if you load to book specs,I've never had any Savage chamber that was too short for a 2.260" OAL.
It doesn't cost much to buy the Hornady OAL tool and a modified 223 case to measure your chamber,then you can find out everything you are wanting to know.
 
Well, I suppose there would only be seating them deeper to avoid getting them stuck in the chamber.
And that is only if they are not crushed to death with a tight crimp. :)

I must qualify this with the admission that the only factory rifle ammunition I have ever shot was twenty two long rifle. I have one box of Fiocci two twenty three and one box of Hornady thirty aught six, both of which have not been used yet. I got the reloading dies in the mail before I got a chance to use them. Since I began handloading I haven't shot anything but my own. I only shot pistols before then.
 
A 69SMK, pushed moderately into the lands, measures 2.258 COAL, and 2.881 with the Hornady ogive checker. Of course, unless they are reeeaaal careful making those comparator parts, and I bet they aren't, you're ogive comparator and mine won't read the same.

The COAL is a little squishy with SMK's, IMHE - if you look at the tip they are actually pretty ragged. I know that a seating die that bears on the ogive will generate rounds that have the same ogive-to-base length, but the COAL will vary a few thou. And there is also variance from how hard you jam into the lands when using the checker.

My Sierra manual lists a 69SMK COAL of 2.260, so 2.258 is indeed a short leade. And silly me didn't save the measurements from when the gun was new - the current measurements reflect several hundred rounds of wear. Eventually I'll be able to load to book length!

FWIW I bought some Federal Gold Medal Match loaded with 69SMK's, and it was loaded to a COAL shorter than Sierra's. Finding out why my Sierra length far-from-max powder loads were showing cratered primers while the Federal GMM didn't was what led me to buy the comparator setup.

(at the risk of stating the obvious, if you load to shorter than book length, be careful. On one hand not jamming into the lands can lower pressure, and on the other a shorter COAL means less internal volume which can raise pressures - watch your onions)
 
RussellC said:
Ok, the 69 grain SMK is one bullet I like to use, do you mean 2.300" or 2.230"? If 2.300, something may need reamed in my chamber. If 2.230, then I need to shorten my 69 grain loads to 2.230...

Russellc
Click to expand...
The 2.300" is correct. Any longer and they dont feed from the magazine well.

When the 69 gr SMK hollow point is contacting my rifling, the OAL for case head to tip of bullet is 2.422" The head to ogive measurement is 1.989"

The 53 gr Sierra OAL when contacting the rifling is 2.353" case head to tip of bullet.
The head to ogive is 1.993"

Average of 3 each.

The gun has over 2200 rounds fired, so throat may be a little longer than the SAAMI standard 1.857" head to ogive. Plus my measuring system is from the dark ages.
 
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Ok, this is not similar to what I am experiencing. When I just put a 53 grain Sierra at 2.250 and shut the bolt, then open it, I have to use a slight amount of force to open it, and the bullet was pulled enough for the cartridge to measure 2.270. I put another size smaller bushing in, just to make sure it didnt slip to easily and set it at 2.240 and it reduced to 2.238 and stayed there. Sounds like something is wrong with my chamber. If I can only get 2.238 and yours is seeing 2.353 I think I have a problem. I will fiddle and listen for a while and if no resolution it goes back to Savage.

Oh, I checked the scope mount bolts, and that wasnt it.

Russellc
 
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I am out of the 69 grain SMK, but I have some loaded and will take one apart and make a dummy out of it.

Russellc
 
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