What was the temp when you were shooting? Was the chamber warm and how long did you leave them in a warm chamber?. I have a 204 that I shoot with h335 and if I want to keep from getting flyers, I basically have to keep the ammo in cooler to keep them the same temp and cannot keep them in the chamber very long. If I follow my procedure this is extremely accurate animal but as soon as the power gets warm I get Flyers all over the place.
A Savage 6.5 Creedmore would not chamber Hornady factory ammo. The guy said a shorter COL was needed, so he seated the factory ammo to a shorter COL.
The rifle was returned to Savage and an adjustment was made to the throat.
I did not get to see or measure anything, so take it for what its worth.
Someoldguy
40º, I'd shoot 1 -5 shot group, make some notes, then shoot a second 5-shot group, change the target, more notes, etc.
Barrel never got over barely warm to the touch, cartridges never stayed in the chamber longer than it took to close the bolt, get on target and squeeze . . .
I also observe on my copy of SAAMI specifications for the .223 Remington that the freebore area diameter is to be .224" When I measured 10 of the Hornady V-Max bullets, I found the diameter to range from .2242" to .2244". I find it difficult to believe that .0004" will cause a bullet to lodge in a .224" freebore, provided it was originally cut at .224". Particularly after the rifle has been fired multiple times. I can not say precisely how many, because I purchased it used. I myself have fired approximately 200 rounds through it.
SO. I'm back to a chamber cast. It appears the freebore in this barrel was cut undersized.
Lucky me.
Chamber diameters shown in a SAAMI cartoon are spec minimums generally subject to a +.002” allowance.
How much runout was at the neck OD and the bullet bearing surface, relative to the case body (shoulder)?
Someoldguy
A good question that I wish I could answer, but can not. Sinclair case gauge is in route from Brownell's.
I can tell you it was 1x Winchester brass fireformed in this rifle and only sized in a Lee collet die. So I expect run-out will be fine.
I don't think it would matter much in this case as I'm getting hard contact all around the base of the ogive with no land contact visible at all? Or do you see things another way?
As to the SAAMI spec, that means the freebore should be .224" to .226", correct?
It would appear mine falls below .224".
Won't know for certain without the chamber cast though.
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there have been a lot of threads about 'what is jam' 'where is jam' and 'what are you contacting when you make contact' (to paraphrase). i have a model 12, but only had 53 vmax, not 55's, so i looked deeper into how i make those measurements.
i use the cleaning rod and 2 stop collar method to get a coal starting point. i thought i had a good technique, but now am not sure. when i measured to a light yet firm contact it was 2.312. jamming the bullet with a pencil measured 2.360. seating the bullet long in a dummy case and chambering measured 2.366. Only on the dummy case method did i get any land mark engraving and it was enlongated and back toward the bearing surface. so question is, what is the 'real' number, or is it only necessary to have 'some number' and work from there?
anyway, maybe it's just this particular combination of bullet design and chamber cut that makes the contact vs jam number so different?
oh, also i tried h335 but didn't stick with it. seems like i had big es too.
I would be inclined to try another powder, something like Varget or Benchmark and see how that goes. If you don't get results with either of those then I would look at the barrel. I had a similar issue with a 300 Win Mag and after hundreds of rounds, I found out it was the barrel. just my .02
polish a bullet seat it shorter than last time, and chamber
look for marks on the bullet.
if you see elongated marks you were "jam'd" you want marks lite, hard to see to be at touch.
look for marks on the bullet.
if you see elongated marks you were "jam'd" you want marks lite, hard to see to be at touch.
Maybe I missed it, but I can't find in any of your posts, how you checked your COAL.
If you did it with an empty case with a bullet in the mouth, did you try to duplicate your results with the bolt out and drop a bullet into the chamber/throat and tap lightly on the back of it with a cleaning rod. Push the bullet out from the muzzle with the cleaning rod. Compare the two.
Jim
Someoldguy
I removed the extractor. Used a neck sized case fireformed to this chamber. Left the bullet seated long, closed the bolt with a bit of effort. Removed the bolt and had to knock the dummy case out with a cleaning rod. Repeated this 3x with 3 different bullets, and all contact I saw was at the edge of freebore/bullet bearing surface. No land contact evidence all 3 times.
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Someoldguy
I'm thinking the freebore diameter is under .224". Won't know until I have time to chamber cast it. Perhaps this weekend.
Someoldguy
It appears to me that the freebore diameter on my barrel is under .224". I'll have to make a chamber cast to find out. I'll reserve judgement on H335 until I know if my chamber freebore is under spec.
i do not disagree with your findings but do think you should redo the seating depth.
your case was too big for the check. size a case that the bolt handle will close on with
NO effort. now with a polished bullet load to the number you found, chamber and extract.
it should not stick. if the bullet sticks it is too long load shorter and redo. redo til, with a magnifying
glass you can just barely see marks...hopefully one for each land.
your case was too big for the check. size a case that the bolt handle will close on with
NO effort. now with a polished bullet load to the number you found, chamber and extract.
it should not stick. if the bullet sticks it is too long load shorter and redo. redo til, with a magnifying
glass you can just barely see marks...hopefully one for each land.
Try the 53gr VMAX . It has a higher bc (.290 )than the 55 and 60 . It shoots well in 3 of my 223's . I use 26.4 grains of h335 in a 20 inch barrel to get 3280 fps . I buy these for $17 per 100 and love them .
Someoldguy
The bolt would close on the fired case. It was once-fired brass and needed no sizing other than neck sizing.
I apologize for omitting that part.
I will check it again and make a chamber cast before I decide if it is a barrel problem.
Thanks for all the replies.
inked up a 53 vmax and i pretty much see the same thing. used my cleaning rod technique and compared the marks on the vmax and on a 50 tnt which has even shorter bearing surface.
tnt firm contact is 2.354 and jammed into contact was 2.359. (5 thou delta)
vmax firm contact is 2.312 and jammed into contact was 2.356. (44 thou delta)
i could feel the vmax yield and move forwaard as i pushed it in, whereas the tnt came to more of an abrupt stop. I also measured the vmax as slightly (<0.4 thou) larger on the shank than the tnt.
let us know what you find with the casting...
Someoldguy
Absolutely. Friday or Saturday I should get to it.
Someoldguy
Well, I didn't have any Cerrosafe, but I did have a fireformed piece of brass and some dead-soft lead.
So, now it's fact and not just theory.
.2237".
So, now it's fact and not just theory.
.2237".
the pic is nto real clear but it loiks like a throat just ahead of the smashed lead in the case. in the pic it looks like a band that goes all the way around, and the rifling starts there.
better larger pics with no glare "
better larger pics with no glare "
Someoldguy
Phone camera leaves much to be desired, to be sure. Also found that the bore is looser at the muzzle than at the chamber.
No point putzing around here anymore. Time to make plans to rebarrel it.
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