Keyholing

[broper]

Maybe try a different powder. I have a Rem. 700 VLS. I'm shooting the 32 gr. Varmageddon, with 30 gr. BLC(2) and Rem. 7 1/2 primers. I got one group that measured .194 c/c. I've never had any key holing with that bullet and powder in my gun. Maybe it's just a case of different strokes for different guns. No two guns ever shoot the same. But if I were you I'd try some different powders, maybe different primers, different OAL. Just experiment. That's part of the fun of working up a new load. To me anyway. Just thought I'd mention my experiences. Good luck finding the sweet spot load for your gun.
Bob

[Tokimini]

Thanks for the tips Bob. For powders I've tried 8208XBR, Reloder 10X and CFE223 and have had the best results with the CFE223. I have also tried various bullets, primer, and OAL combinations. You're right that a good part of the fun of reloading is trying new components. It would get boring to load the same stuff over and over again, and if you don't try new combinations your groups wont change all that much.

[broper]

Sounds like you've tried pretty much everything. I've been wanting to try CFE223 but my gun shoots so well with BLC(2) that I just haven't tried it yet. I've never seen a bullet keyhole as bad as yours did. Have you tried giving the barrel a good scrubbing? I just spent about three hours getting mine down to bare metal. I had used normal cleaning products then foaming bore cleaner. Got quite a bit of copper out, thought I had it as clean as possible. Then at the suggestion of John Barsness I tried Montana Extreme Copper Killer and got even more copper out. Took about three times running that through the barrel before I quit getting coper out. Just a suggestion, might help. Hope you get it figured out. That can be frustrating.
Bob

[Fred_C_Dobbs]

Tokimini, I wasn't offering opinion, I was stating fact. It is a universally accepted principle of ballistic science that bullets in general grow more stable the faster they're driven. To quote Bryan Litz, from Applied Ballistics for Long Range Shooting, Ch. 10, Bullet Stability (p. 150), addressing whether a reloader can materially affect the stability of a bullet by loading hotter: "...[T]he effect that increased velocity has on the rigidity of the spinning mass is slightly greater than the effect of the strengthening of the overturning aerodynamic torque, so the result is a slight increase in stability from the higher velocity...." Translation, faster=more stable.

This is from JBM Ballistics' online Drag/Twist calculator. I didn't use the 32-gr SBK because I couldn't find its dimensions and don't have one to measure, so I used the dimensions from the 175-gr SMK, which is listed in the appendix to Litz's book.



Once the bullet is clear of any transonic effect(s), the Miller stability number (column at far right) increases progressively with MV all the way to 5000 fps. Granted it's not the 32-gr SBK but the result from any bullet will be the same (unless the bullet is driven so fast as to cause it to fail in flight, in which case it will disintegrate, not tumble).


Second, bullet stability doesn't come and go like the flipping of a light switch, in rises and falls in sync with the RPMs. Unless your loads have an extreme spread that looks like a zip code, all 10 of your rounds should have had near identical stability. So if you get nine round bullet holes in the target and one keyhole, that's evidence of a problem with the one bullet.


Third, even the max load you tested wasn't particularly hot. Hodgdon's load data says a max charge of CFE223 will get you at most 4091 fps with a 32-gr V-max from a 26" barrel. So I ran the numbers in QuickLoad, using the 32-gr SBK and enough CFE223 to get me to 4091 fps. When I backed the charge down 3% by weight (30.0 ÷ 30.9 = 97%), QuickLoad predicted 3971 fps. Considering how many hot-rodders have been drawn to the .204R, does it not strike you odd that the Interwebs haven't been flooded with speed demon reloaders complaining that the 32-gr SBK loses stability if driven too fast? Or that out of what must be hundreds of shooters loading for the .204R, you were the first to make this discovery, ...even though you're only running 97% of a max charge?


Lastly, there are three posters to the database at the reloader's nest who state they drove the 32-gr SBK to in excess of 4000 fps, and none noted any stability problems. In fact, the fastest among them claims he got to 4270 fps, probably at least 300 fps faster than what you're getting, and he says it was grouping 0.2" @100 yards. That's a slightly smaller group than I would expect if the excess velocity were going to produce tumbling.


If you only got one shot in 10 showing any signs of instability, either those particular bullets were flawed or something quirky happened to those rounds. Regardless, whoever fed you that line at Sierra needs some education in remedial ballistics.

[RAMOS]

CAUTION: Temporary Hi-Jack!!!

Fred, I have come close to ordering Bryans' book several times. I have held off because I do not know anyone who has read it and have not had the opportunity to peruse it. What is your overall impression of the book in regards to how well an "average Joe" can absorb and use the information?

Thanks,
Jon

[Tokimini]

Thanks for the info Fred. Very impressive, but like I said before, Sierra said back off on the load and the keyholing will stop. It did.

[Tokimini]

Bob, I cleaned the crap out of the barrel about 2 months ago, the most rigorous cleaning I've ever done on the gun. I used a bronze brush, which I have never done before, and Hoppes and a foaming cleaner. I was appalled at all the junk I got out of a barrel that looked completely clean. I must have worked on it for over two hours and when I got to the range my groups were some of the worst I've ever gotten. I'm just now getting back to what I consider acceptable groups. Maybe I just have a squirrely rifle that likes a dirty barrel.

[Gube]

Some old info in regards to the 32 gr SBK's tumbling. I did not do any further testing in my T3. I figured if I have to load at minimum charge to prevent the tumbling out of my savages, I would be better off using the 32 gr noslers and the V-max's instead. My overall favorite is still the 39 gr bk's for busting up ground squirrels .


http://www.204ruger.com/forum/viewtopic ... t=tumbling

[Tokimini]

Thanks for the link Gube. That made for an interesting read. I wonder if Sierra is aware that the 32s have developed a reputaion for tumbling at higher loads in the 204? I think I'll email them the link to that page and see what they say.

[Volstandigkeit]

Any chance the jacket is to soft, and is being stripped?

[Tokimini]

Any chance the jacket is to soft, and is being stripped?

From the shape of the hole the bullet put in the paper when it went through sideways it would appear the bullet was intact

[Tokimini]

Some old info in regards to the 32 gr SBK's tumbling. I did not do any further testing in my T3. I figured if I have to load at minimum charge to prevent the tumbling out of my savages, I would be better off using the 32 gr noslers and the V-max's instead. My overall favorite is still the 39 gr bk's for busting up ground squirrels .


http://www.204ruger.com/forum/viewtopic ... t=tumbling

I emailed Sierra a link to the above thread about the 32gr BKs tumbling and here is their response.

Hi Tom, thanks for the email.
Yes, we are aware of the tumbling issue as well as the occasional disappearing shot. Under normal circumstances the cure is as simple as a good thorough bore cleaning with a good carbon remover followed by a copper remover. I have had excellent personal results while using Witches Brew from Darrell Holland and Bore Tech Carbon Remover followed by Bore Tech Cu-4 Copper Remover. The Witches Brew is a mechanical cleaner that works very well and is most effective when used with a good brush.
The Bore Tech products clean chemically with the help of a patch and or a nylon brush.
Either method is effective and, if deemed necessary one can follow the other as a check. I’d suggest leading with the mechanical and checking with the chemical however.
Bottom line is I think the fouling contributes to the bullet failures almost 100% of the time. The remainder of the time it is a rough throat that causes the problem.
Hopefully the thorough cleaning will solve your issues and that is not to say you don’t know how to clean a rifle but that pesky carbon buildup is very difficult to see with a bore scope even for the experts.
I also appreciate the link 204 Ruger hunting.com . That was very interesting and I can honestly say I had never visited that site so thanks for the insight but I was distressed to see the bullet example. Luckily we got that issue resolved to the customers satisfaction. One down and one to go if I read that right.

Please keep me up to speed with your barrels performance. I’m very interested in your experience as we haven’t had many of these recently.
Thanks again for bringing this to our attention.
Rich Machholz
Ballistic Technician
Sierra Bullets

[hemiallen]

Thanks for the update.


My FIL was running a 22-250 AI and had an issue of key-holing, albeit much less than your target. After a conversation with Sierra the Tech he spoke to said he had the same experience with the BK bullet my FIL had issues with, and to fix the problem.......... Drumroll......Use side cutters and remove the poly tip. He did, and it fixed the stability issue.


He has since moved to another bullet for Beldens ground squirrels, never trying them to see if they sent Skippy flying apart or just DRT.


Allen

[bow shot]

Fred C., I don't understand... I have pics (somewhere...) of targets that show a sideways- hit by my bullets. Isn't that "tumbling" or some form of sideways flight?

I respect your data... but I have paper like Toki's...