Excessively loud report with my 204: Potential cause

[Cyres]

Previously I have posted on here about the issues I have had with occassional very loud reports and missed foxs. Several members suggested possible causes but I have now found the cause?

Reloaded some more rounds 39 BK 25.2 10x, (weiged on electonic balance) Remmy 7.5 primers, 2.250 3,550 fps standard load for excess of 6 years. Went out to test and set up taget on big field of newly sown maize, bone dry. First round fine and on target. Second round very loud report nothing on target. Same happened on third. 4th fired nothing on target but puff of dust 30 yds away from target. Gave up. Long chat with friend and checked everything even dismantled moddy to find baffle looking excessive ragged and entry hole distorted. Clearly bullets touching moddy. Out next day tried again without moddy. Several excessively noisy reports and bullet fragments hitting soil. So 39 BK were coming out of barrel in bits!

Next day shooting mate came round and looked down barrell and decided to give it a very good clean. Normally use Forest bore foam and nylon brush. This time used bronze brush. One very tight spot. Gave it very thourough clean.

Out in afternooon and tried again. Without moddy 3 39 BK only 2 hit target 3rd disintigrated. Then tried some different home loads. Bergers without moddy almost 1 hole group, put moddy with .243 diffuse on and Bergers, 40 vmax all grouping well. Some old 39 BK shot well!!!

So it appears my current 39 BK load is faulty and I am tempted to say I might have a duff box of bullets. Mate has kindly found some old 39 BK so have reloaded and will try. Also another mate has just got a new Tika in .204 so will try some 39 BK reloads in his.

I will update on results

D

 

[Dazb1967]

Very interesting, Thanks for sharing

 

[palo]

I had a similar experience years ago with 39sbk in my 204.
I can't remember if the report sounded any louder but I remember shooting at a target at 100 yards and some of the shots never hit the paper while other shots landed in the bull.
I took a shot at a rabbit one day at 200 yards . I missed and my mate said he seen a bullet strike at about 100 yards in front of me.
I put another round in the chamber and fired again and dropped the rabbit.
I put it down to a bad batch of bullets that came apart before reaching the target.
I didn't have a moderator at the time.

 

[DCG]

I wonder are these seated with just neck tension or do you crimp ? Guess you can see were I’m coming from.

 

[palo]

I wonder are these seated with just neck tension or do you crimp ? Guess you can see were I’m coming from.

Mine were seated with about 2 thou of neck tension. I also clean the bore after every outing.

 

[DCG]

Mine were seated with about 2 thou of neck tension. I also clean the bore after every outing.

Interesting, sounds like the bullet is delaminating, I was wondering if this might have been caused by excess tension in the seating / crimping operation. I guess not.

 

[Mr. Gain]

I also clean the bore after every outing.

I get the impression you should clean it with something else.

 

[palo]

I get the impression you should clean it with something else.

Nothing to do with cleaning , bores are cleaned properly .
It was only an issue with one box of bullets, never had it happen since.

 

[bryn]

Interested.
bryn

 

[Mr. Gain]

Nothing to do with cleaning , bores are cleaned properly .
It was only an issue with one box of bullets, never had it happen since.

My mistake. I meant to reply to Cyres' comment:

Normally use Forest bore foam and nylon brush. This time used bronze brush. One very tight spot. Gave it very thourough clean.

 

[bryn]

I have had similar issues with the 39 sbk.

bryn

 

[Cyres]

I can check this. Its Winchester brass which has been annealed. I use either Redding Type S bushing type dies with a .226 titanium nitride bush or a Lee bullet seating die. Not crimped.

Will also try with brand new Winchester brass in both dies.

D

 

[Cyres]

Re cleaning. Have always used Forest bore foam and nylon brush followed by Bore Tech Elliminator.

Latest cleans as above but with Phosphor bronze brush then patch out till clean patches. Use bore tech stainless cleaning rod.

D

 

[Blind Pugh]

I've read somewhere recently (cant find it again) an apology from Sierra to all their customers about a bad batch of 204 bullets that went out around July 2020 .

 

[zambezi]

I've read somewhere recently (cant find it again) an apology from Sierra to all their customers about a bad batch of 204 bullets that went out around July 2020 .

Per this link, Sierra did have a batch of .204 cal bullets adulterated with some .22 projectiles and apologised for same in 2014. Whether your bullets match that lot number or not, perhaps check OD on remaining bullets? BP recalls this happened in 2020. So perhaps it is an error they have made more than once?

problem with Sierra 20 cal 39 gr Blitzking

Recently purchased a couple boxes of these from Midway for a proven 204 Ruger load. While reloading I was seating bullets and felt a bit more resistan...

www.24hourcampfire.com

 

[zambezi]

...and I found this 2018 apology on the Sierra Bullets website:

Sierra Bullets

A tradition of precision since 1947

sierrabullets.wordpress.com

 

[Blind Pugh]

Probably that... my error. Apologies.
Back to the problem,
1 Would try using that batch in another rifle
2 Measure a dozen . will need a micrometer because you would only be looking for a few tenths of a thou.
3 Try another batch

 

[Cyres]

Quick update. Went out last Weds and shot at 150 yds. 40 v maxs about 2" group crap. 5x reloaded using some older 39 BK went into about 3".

Re tried current batch of 39 reloads. No bullets on target. No excessively loud reports. Drove up to 20 yds. First two about 2" 3rd lovely key hole about 4" away. Mate then tried with new Tika T3 varmit. 2 shots almost through same hole. 3rd keyholed about 4" away. He then tried minus moddy and next one keyholed.

So we have a load for 39 BK which used to bug hole which is unusable in 2x different .204's

My 40 grn v max when shot through Tikka were silly accurate and averaged 3698 fps SD 10.1 ES 22 ( 25 grn 10x Rem 7.5 2.250 Winchester brass)

Tried some 30 grn Barnes and shot about 10mm

Next step reloaded some 35 and 40 grn Barnes in brand new Winchester brass. COL 2.260.

40 grns useless all over the place, 35's best was 1/2" at 100 yds.

Tried mates 32 Varmagedons very good accuracy. His bug hole.

So current situation is:

Current batch of Sierra 39 BK will not shoot out of my 5 yr old Savage and a new Tikka T3 Varmit. 25.2 10x Rem 7.5 Winchester brass 2.250

My Savage appears not to be able shoot 40 grn Vmax, Tikka accuracy was excellent.

32 grn bullets appear to be accurate in both rifles.

So is my barrel on the way out and or is the current batch of 39 BK deffective?

Both rifles are 1:12.

D

 

[palo]

I think your current batch of 39bk are defective as they are erratic in both rifles.
As for the 40 grain vmax some 1/12 twist barrels will shoot them and some won't.
From my experience ruger, tikka and sako rifles shoot the 40 grain bullets fine but remington rifles won't.
I have no experience with savage 204s .
If your rifle is shooting the 32 grain accurately I would use them in the meantime but I would try a different batch of 39 grain sierras again in both rifles.

 

[ss03947]

Sounds like a bad batch of bullets to me.
Different bullets, (Hornaday SX iirc) but problems the same, flip through to 10-11mins in the utube vid where he's going through his days shooting on the computer.