Help! 6Dasher Blanking primers

R

Ramsh00ter

Guest
Got some questions:

Shooting Panda with 28" Boughton barrel 8 1/2 twist, 6mm Dasher, 105 grain Scenar, CCI 450 primer.

Last time I shot this rifle in a match, I blanked a couple primers and got crap back into the bolt. Gun would not fire until I completely cleaned out the bolt.

I was shooting tonight trying out some RE 15 and IMR 8208.

I started with 32.8 grains of RE 15, blanked one primer. No pressure signs
Next three loads were 33.1, 33.3, 33.5, didn't blank any primers. No pressure signs.

Next load was 31.8 grains 8208, blank one primer out of 3, very slight pressure signs, bolt was easy to open.
Next load was 32.1 grains 8208, blanked two primers of 3, same pressure signs, easy opening bolt.

I did not break out the chrono, so I am not sure the velocities between the loads. They all printed pretty close to the same point of impact.

Started thinking maybe firing pin was too long?

Measure it against two other Pandas and they were all .049" to .051" out from bolt face. I checked one from a Teddy, it was out .060". So I don't think it the firing pin length?

Arn't the CCi 450's supposed to have a thicker cup?

I havn't had a rifle blank a primer in years.

Any ideas? I'm stumped?

Randy
 
Blanking IS a pressure sign :)

Firing pin length and spring tension have nothing to do with the blanking.

Your pressure is too high for the size of your firing pin hole. your options are to drop the load or bush the firing pin.

opinionsby





al
 
Thanks Al

That is what I was thinking, guess I need to back it off a little.

Thought I was starting low.

It shot really nice at 33.3 with the RE 15 and none of the higher loads blanked?

Think I will try some loads around 32. to 32.5 tomorrow.

Will post the results.

Randy
 
Randy I have had the same problem in my 6 BRX, tried several things and the one that did the trick was a smaller firing pin .062 and bushed the pin to fit no more problems. Greg Tannel did the work very reasonable and quick turn around
Cost me 2 repairs on my Jewel trigger before i went to a smaller firing pin. Now i can run 33.6 gr Varget and no pressure and no primer problem( IN MY RIFLE!)
In my Remington action when the primer is blowen the gas comes back through the bolt and pushes the firing pin back and takes out the spring in the trigger so it will not cock the rifle . Dave
 
Randy Sir, I may add that on my dashers with RL15 I see pressure at 31.6 at 93 degrees on 2 different barrels and with 32 at 81 degrees.33.0 would prebably blow up my gun .Hope this helps sir. Tim in Tx
 
Guys, Thanks for the advise and input.

Regarding bushing the bolt, how much clearence do you end up with? The bolt on this Panda seems to have a slip fit to the firing pin. I did not feel any play in it. Of course this is a rough test of just inserting the pin into the front of the bolt.

Or is because you going to a smaller firing pin?

One of the differences that we may be dealing with is the bullets. Most of the reports of guys using 33.5 grains of RE 15 are with Berger bullets. I am shooting Lapua Scenars. I do not know for sure as I do not have a Berger to compare, but I believe the Scenar has a longer bearing surface?

With that and possibly a different copper compound, that could explain the increased pressure?

When I did my load testing, I did not see any better groups at the higher node.

The gun shoots very well at 32.5 grains (that is what I shot Sunday). I missed 6 shots out of 50, two of them were the jerk behind the trigger! Two were unexplained, but prob wind. The other two I know was the wind. So I can not complain about the way it shoots.

When I looked at the shot placement on the Silo targets, they were pretty consistant all the way out to 600 yards.

Does anyone have a phone number or email address for Greg Tannel, think I would like to call him.

Again, Thanks for all the input.

Randy

"Life, Liberty, and the pursuit of those that want to take it away!"
 
Last edited by a moderator:
I think the Panda has a .062 pin and it should be tight. The other two examples were both Remingtons. Matt
 
Hi Randy ,Yea you are right I was speed reading again ,I was referring to bergers. But have shot both berger 105 vld and scenars and looked at my data and by aver the scenars are about 27 fps slower then the bergers with the same powder charge and maximum pressure powder differences is only .3 of a grain apart at the same temp.Not as much as I would have thought considering as you said bearing surface and might add the berger diameter averages .0004-.0005 larger than scenars with a snap micrometer or indicating micrometer. The largest diameter being at the boatail on bergers and aprox. .300 in front of the boatail on scenars. but the scenars have an average of .070 longer bearing surface then the berger,So I think there is and offset of dia vs bearing surface creating fairly close results with the 2 bullets. Tim in Tx
 
You must log in or register to reply here.
Back
Top