Chamber Length -Updated 4-9-05

dcloco

As you can tell from the other thread on this forum, I am just beginning to reload. Primary reasons - cost effectiveness and accuracy.

I purchased a Savage 12FVS in .223 - bull barrel, single shot, sythetic stock.

No, I am not expecting benchrest accuracy, but I have tried 25+ over the counter ammo...and the groups are terrible. 3-5".

Have not reloaded a round yet, but as I have stated earlier, I have read anything and everything that I can get my hands on. I have four reloading manuals, besides the internet (no, I don't believe everything I read, but can usually tell who is just blowing smoke).

My question....other the counter rounds measure 2.250 +/- 0.002. After cutting the neck on the case, I inserted a bullet in the base, chamber the round, and let the bullet be pushed back in the case, so that I could measure actual chamber length. On my rifle, the chamber length is 2.410.

In most of the reloading manuals, the specs provided for overall cartridge length is based on the AR15 rifles.

How close to the lands or how far from the lands, should I seat the bullet?

jimbowby

[8D]Yo dcloco,I don't know what the bore twist/inch that you have, but unless unless you're very new at this and I assume you're shooting at 100 yd's, you don't mention a scope, but with factory ammo and even open sights (a good shooter) can get 5 shot groups of 2"or less. You can't expect reloading to improve you combo THAT MUCH. You'll have to provide a lot more info my friend[:)][:)][:)][:D]

I'm only wearing Black untill they make something darker

dcloco

Savage 12FVS - 1:9 twist, bull barrel.

6-24x44 Scope on Leopuld base & rings.

Not a new shooter...just medium experience with a new rifle.

Tailgunner1954

While a lot of guys believe in the old MYTH of being close to the lands for best accuracy, and say 1/10 of the bullet diameter off the lands (.022 in your case), your magazine will often set your max length. OAL tuning is a fine tunning of the barrel harmonics, not sonthing to worry about in the early stages.
What your measuring BTW is throat length, not chamber length.
Accuracy reloading is a process of reducing the variables and fine tuning the ammo to match the rifle.
Work through the following list, in order.
Tune the shooter
Check scope mounts
Check bedding
Tune the trigger
Sort your brass, and use only 1 brand (no mixing)
Find the bullet weight that your rifle seems to like best
Find the bullet style that your rifle seems to like best
Find the bullet brand that your rifle seems to like best
Find the powder brand that your rifle seems to like best
Find the powder charge that your rifle seems to like best
Find the primer that your rifle likes best
Find the OAL, for that combo, that your rifle likes best.
Each rifle is a law unto it's self, so what works for someone else won't necessarly be the perfect combo for you.

---

Some guys like a mag full of lead, I still prefer one round to the head.

sandwarrior

Dcloco,

I have a Savage 12FV and it shoots great. I found my best loads were 60 gr. Sierras and 55 Hornady v-max's. For some strange reason it doesn't like to stabilize the 69's even with the 1-9 twist, unless I push them really hard.
I would suggest doing what some of the other posters have said. Also, how did you break in the barrel?

If you are having continued accuracy problems beyond what you have already checked ask your gunsmith to boroscope the barrel, if it's defective Savage may replace it. -continued luck with your rifle

We have the second amendment so that all the rest are secure....UNK>

JustC

I ASSume you are at least a decent shooter, and that being said, with the number of factory ammo's you have tried,..if all you get is 3-5" groups, you have a serious problem

Check the stock/action screws
check the rings for tightness
TRY ANOTHER SCOPE!!!!

NO way that rifle shoots that poorly without a SERIOUS manufacturing flaw.

Now, other than that, your chamber measurement has some flaws, but for most applications will work (jamming them will quite often yield a fair amount of scarring on the jacket and points to the fact that under the pressure of the firing pin spring and the ejector plunger, it has been shoved INTO the lands quite a bit, which gives a false measurement). The seating depth in the books is SAAMI spec, and useless in MHO. I find the OAL for the pill to be at the lands, then back off (for a carry rifle) maybe .005-.020" and start loading. For a match rig,...it may be into the lands by up to .010" Now, do a search on Partial Full Length sizing, and follow the directions for sizing your fired cases for max reliability and accuracy combined.



why chase the game when the bullet can get em from here?....
Got Balistics?

FrancF

As the others have said 3"to 5"? or did you mean .03" to .05" inch?

If you are shooting 3" @ 100 yrds with a Savage 12FVS in .223 - bull barrel, single shot, sythetic stock, something is up! That gun on a bad day should shoot nothing more than 1/2 inch at that range.



NRA Life Endowment Member

dcloco

Best @ 100 yards - is 1.25". Worst...is 5".

Have probably sent 200 rounds (at least 25 different brands, bullet weight, etc...everything from Wolf to Winchester - 45 gr to 62 gr).

It is not the shooter....accomplished no. I am "above average"....but not of a benchrest shooter caliber.

I will try another scope before I reload anything..just to rule that out.

I am still wondering out loud on the OAL...look in your reloading book...all of those rounds are designed around the chamber for an M16/AR15...not a single shot, bull barrel rifle. Also, most, if not all of those loads are worked up for a 1:12 twist...not a 1:9.

Tailgunner..that is the most complete workup/thought process that I have seen yet. Good info. Thanks!

Thanks to everybody...will keep going forward and let everybody know.

jimbowby

[8D]Yo dcloco, you said, best 1.25" worst 5.0"- which one was the best and yes most Reload manuals base on AR/M16 rifles, but ALL factory ammo works in ALL. I can get 1.5" groups with UMC .223 $3.95/box ammo- there's always more than the machine IE: 3-shot/5-shot, cool down time ,breathing, heartbeat, right/left hand pressure/Sling swivel interference /scope parallax adj/focus-on and on and on, they say Weatherby shoots Better than 1.5" out of the box, but you take any 300 mag out of the box and shoot under 2.00 in initial groups and your either a liar or great bull snoter.[}:)][}:)][:p][:D]

I'm only wearing Black untill they make something darker

dcloco

Jimbowby....I got your point....and try the best grouping ammo on the 5th & 9th targets...with very similar results...1.5" groups...so..repeatability is there.

NO scope adjustments after initial.

Thanks again.

jimbowby

[8D]Cool man, now get you bullet weight Gr. right, seating depth/ Case similiarity/COL/AOL? powder weights within .oo5 GR(At the right weight)No rear swivel bolt/front swivel bolt right tension/same shoulder pressure/EXACT SAME AIMING SPOT/ new ball game![:p][:p][:p][:D]

I'm only wearing Black untill they make something darker

dcloco

LOL...if anything else...just like EVERYTHING else...about the time you "think" you have a good idea about something....I decide I want to reload. ARGH! LOL

JustC

1.5" is the best? then something is amiss. First, swap the scope, even for a $50 throw away that is laying around. Don't bother sighting dead-on,..just shoot for groups again. If the groups come together, your scope needs to go back for repair.

next, rings and bases need checking. take the scope out of the rings and see if that front ring isn't slightly loose. then check scope bases.

now, 65 INCH/lbs is the stock torque you need. loosen the screws and tap the rifle on the recoil pad several times on the ground to seat the recoil lug, then as you press on the muzzle toward the butt, tighten the front and rear alternating back and forth and working your way up in torque. General rule according to badger Ordnance (if you don't have an in/lb torque wrench, then go finger tight, then another 90 degrees NO MORE)

Next, thorough copper cleaning with an agressive solvent such as Sweets 7.62 or Wipe-out foam.

One of these should show the problem,..if not then the barrel could have an imperfection which may or may not be visable with a light in the bore after a cleaning. Look for a change in the rifling or a dull spot in the bore.


why chase the game when the bullet can get em from here?....
Got Balistics?

dcloco

Rings, bases, & stock have been checked. I used an inch pound dial indicator torque wrench (use this to rebuild automatic transmissions-calibrated dead on).

Scope is next...maybe tonight? Will have to break down and remove one from another rifle.

JustC

You know, I read an article a few years ago that stated that even a slight loss of zero or wander, was present in something like 90% of the production scopes, right from the box. The problem with this is, that most rifles and shooters are not capable of determining this since the majority of non-catastrophic failures would yield such small amount of drift. Only true benchrest rigs were able to show the results.

That being said, switching scopes is quick, and as long as you count your clicks, you should be able to take them back out, and re-mount the test scope back on it's original rifle without a loss of zero (this is a good time to test THAT scopes repeatability[8]).

If it isn't the scope, that rifle has a factory issue.

Just for the sake of it,.....try folding a business card oven until it requires a fair bit of pressure to run it under the barrel in the barrel channel at the front of the stock. Shoot the best ammo again, and see if the group comes in some,..if so, all you need is a bedding point. If not, back to the scope again. This test is cheap and quick.[;)]

why chase the game when the bullet can get em from here?....
Got Balistics?

dcloco

Will do.

Tomorrow night will be heading to the range after work. ...just me...rifle...TWO scopes...some ammo.....and some luck!

dcloco

No range tonight..40-50 mph winds today. UGH!

dcloco

Just to rule it out...and following everybody's advice...I shot 5 rounds with original scope mounted on gun...and 5 rounds with another scope mounted on gun. Remember...I am just shooting for group, so I mad NO changes on either scope.

I did remove scope base, cleaned, & remounted. I did add a minute amount of epoxy under the base.

ALL shots at 25 yards. Two fouling rounds fired at beginning and after scope change.

4-9-5 I deleted the pics from the 25 yard test.....

JustC

looks to me like a small bit of verticle stringing is taking place (low priced ammo and varying charges????) but judging by that 55gr target with scope #2, I would be looking at your old scope as the culprit. If it wasn't giving 1 hole at 25yds,..I would say it's slipping quite heavily. Try running the box test with it just to be sure.

center the shots,..then dial up 3"(fire), right 3"(fire), down 3"(fire), and left 3"(fire) and see if it hits the first bullet hole. If not, and I am betting it won't, then send it back, that is the problem.

I see 1 knotted up group, which came from scope #2 with 55gr pills. That speaks volumes to me,..but then again I wasn't there so this is all a guess at best.

why chase the game when the bullet can get em from here?....
Got Balistics?

dcloco

Here is the productivity for the reloading on Friday & Saturday night.

Early implications lean towards - this rifle LIKES 69 gr bullets.

Don't cheat and look at the last picture!!

I did purchase an Stoney Point OAL gauge, but this alone will not cure the problem.

Pictures with group size (at 100 yards) as follows:

Sorry...the target did not arrive home with me, but the rest of the backstop did....

55 gr bullets, 25.0 gr Accurate 2230-C, 1.750 case length, 2.250 OAL produced groups of #1 - 2.0" , #2 - 1.55", #3 1.0 "


55 gr bullets, 25.0 gr Accurate 2230-C, 1.750 case length, 2.250 OAL produced group of #4 - 1.8"


55 gr bullets, 25.0 gr Accurate 2230-C, 1.750 case length, 2.250 OAL produced groups of #5 1.125"



50 gr bullets, 25.0 gr Accurate 2230-C, 1.750 case length, 2.250 OAL produced groups of #6 - .937"



50 gr bullets, 25.0 gr Accurate 2230-C, 1.750 case length, 2.250 OAL produced groups of #7 - .687"



50 gr bullets, 25.0 gr Accurate 2230-C, 1.750 case length, 2.250 OAL produced groups of #8 - .800"



50 gr bullets, 25.0 gr Accurate 2230-C, 1.750 case length, 2.250 OAL produced groups of #9 - .875"



50 gr bullets, 25.0 gr Accurate 2230-C, 1.750 case length, 2.250 OAL produced groups of #10 - 1.0"



50 gr bullets, 25.0 gr Accurate 2230-C, 1.750 case length, 2.250 OAL produced groups of #11 - .75"



55 gr bullets, 25.0 gr Accurate 2230-C, 1.750 case length, 2.250 OAL produced groups of # 12 - 1.3"



55 gr bullets, 25.0 gr Accurate 2230-C, 1.750 case length, 2.262 OAL produced groups of #13 - 1.3"



55 gr bullets, 25.0 gr Accurate 2230-C, 1.750 case length, 2.274 OAL produced groups of #14 -1.312"



55 gr bullets, 25.0 gr Accurate 2230-C, 1.750 case length, 2.286 OAL produced groups of #15 - 1.250"



Group shot. 4 targets, 5 shots each - using the same 55 gr bullet, 25.0 Accurate 2230-c powder, CCI 400 small rifle primer, and the same brass. This rifle does not like this 55 gr bullet.



8 shot group (@ 100 yards) of 68 gr bullets, 23.5 gr Accurate 2230-C, 1.750 case length, 2.248 OAL produced groups of #16 - 1.250".



69 gr bullets, 23.5 gr Accurate 2230-C, 1.750 case length, 2.250 OAL produced groups of # 17 - .600"

dcloco

Oh...NO changes were made to the scope during the process. NONE! NADA!

JustC

looks like she is coming together nicely. I still am seeing a bit of verticle stringing in many of those groups though. Have you double checked to see that the barrel is free floated for the entire length with no contact points? if it is,..try the business card under the barrel/forend and see if the slight upward pressure on the barrel takes that verticle out of it.

Also, looks like both the Blitzking and the NBT could be tweaked to be highly accurate as well.

Also, give the lighter bullets just a bit more powder and see if that takes the vertical out of it. I have quite often found vertical to be a powder charge issue. Bump them up a bit,..or if you are at max, then bump them back just a bit and see if that pulls them together.

Enjoy it,..figuring it out is half the fun. That rifle has some potential!! a 69gr pill could be quite nice for long range work too.[;)]

why chase the game when the bullet can get em from here?....
Got Balistics?

dcloco

Will do...on all three suggestions. Probably load some rounds this week...

Yes...the barrel is free...going to check it when the barrel is warm at the range as well.

Thanks to everybody for the help.

dcloco

Will post some more pics this evening....cold is stilllllll kicking my *....but still went to the range!