problem with dogtown 55gr bullet exploding

[rweaver00geo]

just got back from shooting and had several (over 5) of the 30 rounds explod about 50 feet from the barrel.
I am shooting a savage 111 with a 22" 1 in 9 twist
My loads were 25.5 grains benchmark, cci small rifle primer, lc brass c.o.l. 2.198
It was hot and sunny as I shot more the gun heated up I observed 1 pierced primer, several minor cratered primers and 1 severe.
I have loaded this exact powder combo with nosler 55gr and sierra 55gr with no problems other than minor cratered primers.

 

[2clicks]

Re: problem with dogtown 55gr bullet exploding

Benchmark??? Hornady and Sierra don't list a benchmark charge for their 55gr bullets. Must be a reason for it. The Hornady manual lists IMR 3031 which is as close to the same burn rate to benchmark as it gets, they only suggest 22.8 as a max load for 3100 fps... Their COL is 2.200 so your probably ok there. Ammo in the hot sun will cause bad things to happen too. If your looking for speed they list Winchester 748 22.7(Min)-26.4grs(MAX) for 2,800-3,200 fps. This is a much slower powder. I like 25 grs of it for 55 gr vmax bullets. Or you can back way off (for Benchmark) 20.5-22.8 is what they list for IMR3031. (21-22grs of Benchmark might be ok) That's the closest guage I can give you for the Benchmark powder. You should google a burn rate chart and print one off for yourself and use a powder charge close to the burn rate of the powder you have. Good luck Hope I was helpful. I'm guessing to much powder and it doesn't matter if it was ok last time it was probably to much powder then too.

 

[rweaver00geo]

Re: problem with dogtown 55gr bullet exploding

Hogdon lists a 55gr sie sp at 25.6 max charge, I have relaoded this with a 55 grain speer tnt, nosler ballistic tip sierra, winchester with cannelure and hornady soft point with no problems other than slight cratering. I thought benchmark was supposed to be temperature insensitive?

 

[rweaver00geo]

Re: problem with dogtown 55gr bullet exploding

I did pull 4 of the remaining 20 rounds and re-measured the powder at 25.45, 25.5, 25.5, 25.48, so at least for the 4 I measured they were ok? didnt want to pull them all yet. Im going to shoot the remaining rounds at paper targets at 25yards and try to get some irregular holes.

 

[raptorfendercash]

Re: problem with dogtown 55gr bullet exploding

7th edition hornady manual list 24.5 max in 26" 12 twist at 3100

49 edition Lyman list 25.3 at 3137 max in a 24" twelve twist and as you said hodgon list 25.6 right on the can.nothing wrong with using benchmark with 55's.

i dont know this but it is poss that the dog towns may have a thin jacket and you are close to or over max.the 9 twist should have more drag on the bullet than like say a 12 too.i would say back off on your charge.

 

[raptorfendercash]

Re: problem with dogtown 55gr bullet exploding

just food for thought i shoot a 50gr. nosler ballistic tip with 25.5 gr. of benchmark,lapua brass,wolf pri out of a 24" 12 twist at 3564fps and it is a great all around performer.

 

[Fuzzball]

Re: problem with dogtown 55gr bullet exploding

"I am shooting a ... 22" 1 in 9 twist"

You got any idea of how fast those bullets are spinning? They are litterly slinging themselves apart with hot loads and that twist. Your rifle is suited to heavy bullets, not lightly constructed 55 grainers.

 

[rweaver00geo]

Re: problem with dogtown 55gr bullet exploding

I have no idea how fast i bet someone smarter than me can answer that in rpm's.HINTHINTHINT the gun loves every other 55gr so far, and in a wierd way it didnt like the 69 smk even though my other savage with a 24" barrel does? It also shoots great with the winchester 45 grain white box?

 

[B y r o n]

Re: problem with dogtown 55gr bullet exploding

Don't know the vintage of this Sierra data but it shows 25.2 as max for Benchmark and 55 gr pills.

Your problem is probably over pressure and spinning the thin bullets to death.

 

[rweaver00geo]

Re: problem with dogtown 55gr bullet exploding

Thats interesting and ive noticed before slight differences between bullet companies and powder companies in published data. And to be honest I dont have any book data for benchmark so Ive been going by the hogdon website data. I did start 10% below for other loads but since I never had a problem I didnt for the midway pills.

 

[81Z4ME]

Re: problem with dogtown 55gr bullet exploding

Some bullets have thinner, more fragile, jackets to help the bullet "explode" at lower velocities. Sierra and Hornady both used to make .224 bullets for use in .222 Rem., .223 Rem., etc. that resulted in expansion similar to what you'd get firing a standard bullet through in a .22-250 or .220 Swift cartridge/rifle.

One or the other (Hornady or Sierra) specifically advised against using them in the Mini 14 due to the faster barrel twist resulting in "exploding" bullets between the barrel and the target. I just had to try some and sure enough, loads that worked great in my Rem. M700 (.223 with a 1 in 12 twist) when fired through my Mini 14 (.223 with a 1 in 9 twist) resulted in 3 or 4 out of 10 bullets flying apart before they got to the 100 yd. target.

The fragile jackets can't take the strain of the high rpm.

 

[ZY100]

Re: problem with dogtown 55gr bullet exploding

The dogtown bullets have a very thin jacket....so you can better splatter the dogs. At a MV of 3100fps (you might even be higher) your little pills are spinning at a touch over 247,000 RPM. Almost as high as I rev my wife's PT Cruiser in my vain attempts to kill it...but that is a different story.

However, keep in mind the bullets coming apart has nothing to do with how hot your load is, it is simply a function of MV. It appears you are also approaching the max load (WRT pressure) in your rifle under the conditions you shot--hot brass, etc.

ZY

 

[OlsenG_360]

Re: problem with dogtown 55gr bullet exploding

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: ZY100</div><div class="ubbcode-body"> At a MV of 3100fps (you might even be higher) your little pills are spinning at a touch over 247,000 RPM. Almost as high as I rev my wife's PT Cruiser in my vain attempts to kill it...but that is a different story.

</div></div>

That made me laugh, god I hate those things.

 

[Fred_C_Dobbs]

Re: problem with dogtown 55gr bullet exploding

"It is not how much velocity, but rather, how fast is it spinning that counts."

Varmint Al does 2D Finite Element calculations of an exploding bullet.

 

[oldgrayone]

Re: problem with dogtown 55gr bullet exploding

I would as above, thin jackets and fast twist is tearing the jackets off of them.

 

[KIDGLOCK]

Re: problem with dogtown 55gr bullet exploding

Holly shit batman , a CLUE !!!

"It was hot and sunny as I shot more the gun heated up I observed 1 pierced primer, several minor cratered primers and 1 severe."

Just say'n ya might back off a little for hot days .

 

[former naval person]

Re: problem with dogtown 55gr bullet exploding

That is just what "Dogtown" bullets are made to do. Back off a mite and "kill them dogs".

 

[rbt50]

Re: problem with dogtown 55gr bullet exploding

are you sure it is a 1-9,i have add this happen with 1-7 twist barrel and thin jacketed bullets.

 

[rweaver00geo]

Re: problem with dogtown 55gr bullet exploding

im figuting about 3250 fps, I loaded 10 rounds shot great, loaded the other 90 and shot several. i did have a failure and didnt notice it, thought i missed my 2L bottle or sumthin. Then about a month ago with my brother we noticed 2, possibly because we shot more and heated the gun up. Then last week for sure with the ammo & gun in the sun we had a bunch. i have 20 rounds left and didnt get a chance to use them this weekend.

 

[rweaver00geo]

Re: problem with dogtown 55gr bullet exploding

im actually not sure its a 1 in 9 but it is a savage with an original barrel so im guessing 1 in 9 but if it happens in a 1 in 9 it wouldnt it also happen in a 1 in 7 (faster twist rate)

 

[Fred_C_Dobbs]

Re: problem with dogtown 55gr bullet exploding

AFAIK, none of the current Savage 111s is offered in .204. The Model 11 <span style="text-decoration: underline">is</span> offered in .204, as is the 12 but they both have a 1:12 twist.

 

[Fuzzball]

Re: problem with dogtown 55gr bullet exploding

"However, keep in mind the bullets coming apart has nothing to do with how hot your load is, it is simply a function of MV."

It's a little more complex than MV alone. Spin rate is determined by the velocity multiplied by the twist rate. Hot loads certainly produce more velocity.

 

[rweaver00geo]

Re: problem with dogtown 55gr bullet exploding

so how much would a hot bore/barrel and sun have an effect? especially since it started to rear its ugly head after 4+ shot strings on that particular day.

 

[Fuzzball]

Re: problem with dogtown 55gr bullet exploding

"..how much would a hot bore/barrel and sun have an effect?"

Now that's an intangible no one can honestly answer. But the temps you and the rifle could stand are unlikely to make a lot of difference to the bullet

Your problem isn't so much a "hot" bullet as it is the high rpm is slinging the soft, thin bullets apart. It was a common problem years ago when the .220 Swift was new, even with a much slower twist than your's the high velocity was sufficent to spin them faster than some common bullets of the period could stand.

 

[rweaver00geo]

Re: problem with dogtown 55gr bullet exploding

TESTED LAST 20 rounds and I couldnt get a failure. WTF!
Heres what I did. Had a camera to record visual blowup and a thermocouple to measure temp. I placed white paper on blue target board in about the same area where the rounds exploded before. I started at 12:16 pm, air temp 82deg bore temp, temp in sun and bore temp 86. I shot 2 and 3 shot salvos till 12:36 checking the bore temp wich rose to 132. between salvos I left a round chambered for a few minutes to "heat up" but that obviously had no effect. Granted it was about 10deg hotter on the past day but now im stumped. Primers were only slightly cratered. Even with the bullets passing thru blue target board they still hit the steel target 150yards away.

 

[Prairie Wolf]

Re: problem with dogtown 55gr bullet exploding

Midway sez: Keep them under 4,000 feet per second and they will probably outshoot your best barrel!

Most likely, that advice was meant for a 1:14 twist barrel.

at 4000 fps, a 1:14 twist = 240,000 rpm
at a 1:9 twist, 240,000 rpm = 3000 fps

You're spinning them apart, I'd guess.

 

[XTR]

Re: problem with dogtown 55gr bullet exploding

Any time I see a comment that .223s are fragmenting I expect to see that they are shooting 55gr bullets in a 1:9 or faster barrel and they are driving them fast.


Barrels with a 1:9 are designed for a 62gr bullet.

 

[rweaver00geo]

Re: problem with dogtown 55gr bullet exploding


Thats the best info yet, I saw the 4000 fps info on the website but didnt realize it was for a 1-14 twist. wish they had more of a "warning label" that sux cause they grouped as well as the sierra soft points and it did a bang flip on an 11 lb groundhog 90 yards. Should I contact midway for returning my unopened box of 500?

 

[Prairie Wolf]

Re: problem with dogtown 55gr bullet exploding

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: rweaver</div><div class="ubbcode-body">
Thats the best info yet, I saw the 4000 fps info on the website but didnt realize it was for a 1-14 twist. wish they had more of a "warning label" that sux cause they grouped as well as the sierra soft points and it did a bang flip on an 11 lb groundhog 90 yards. Should I contact midway for returning my unopened box of 500?

</div></div>

I'm only assuming that they meant 1:14. The only common rounds that get close to 4000 are the .220 swift or .22-250.

.22-250 is usually 1:14 but some make them 1:12.

As for returning them, I don't know. Sounds like you are pushing them to the edge. Try slowing them down 150 fps, they might hold together and be explosive on critters. Of course you can return one box and experiment with the one you have open.