To bush or not to bush???????

[msinc]

Your a wildman snert!!!!! carlsbad, your pictures are not showing up......

 

[chuckshooter]

Once you become focused on a issue, it hard not to want to get it bushed. But I would certainly look at using a thicker cup primer first and see the results. standard primers are around .020 thickness ..Magnum and benchrest primers are .025 thickness ..you're adding 25% more thickness to your primer .. that should produce less flow

 

[carlsbad]

Once you go bush, you'll never go back. I'm not looking for new work now since my day job as an engineer survived a 95% layoff. I highly recommend gretan, like everyone else. If there is any reason you can't use gretan, I'll always help members here out for the same price, same quality.

--Jerry

 

[msinc]

.............................................................................. There is one more issue that hasn't yet been addressed........................ That is the SHAPE of the firing pin tip as evidenced by the flow of the primer cup at the outer dimension of the pin. There is no need for your firing pin to be this "pointy". Changing your load to accommodate different powders, bullets, charge wgts. or jamming could easily cause your primers to be pierced before reaching best accuracy. Look closely at the firing pin tip in the GRE-tan youtube video and see it is rather flat as compared to the firing pin indent on your primers. A CAREFUL re-contour of the firing pin tip to a flatter contour can easily remedy this condition. ..... NO it won't remedy the excessive chamfer on your F/P hole. But Gre-tan can fix that problem. Ask Greg about these two completely different problems. I've re-contoured at home with 600 grit wet-or dry and solved the problem of primer flow/piercing from excessively "pointy" F/P's............... I'm as a guilty as the next guy of sometimes "not seeing the forest for the tree's"

Yeah, there might be something to this...the photo below shows three 700 short action firing pins. The one on the left is the one in this rifle...you can plainly see that it has a different shape than the one on the right. I will have to go back and review Tony Boyer's book as he has a pretty extensive section regarding the shape of the firing pin tip. I think I will swap out the one I am using now for the more favorable looking one and see what happens.



Edit: I should add that none of these strikers have been modified in any way...they are as received from the factory.

 

[msinc]

Once you become focused on a issue, it hard not to want to get it bushed. But I would certainly look at using a thicker cup primer first and see the results. standard primers are around .020 thickness ..Magnum and benchrest primers are .025 thickness ..you're adding 25% more thickness to your primer .. that should produce less flow

Funny you mention this...I have had this rifle for several years and just rebarreled it. Same caliber, better barrel. back when primers were a little hard to get the local gunshop had some Remington 6 1/2's. They were just all that was available at the time and so I tried them. It pierced absolutely every one of them and I told the guy that he might want to pull them or at least make sure he tells people they are not really for 223/5.56 cartridges. He said,"you are the only one complaining" and I dismissed it as guys that were just glad to have primers at the time. Because of this incident, I know that 6 1/2's are thinner, but I did not know that magnums and BR primers were thicker...I was always told and read that BR primers were a more consistent thickness because the sheet they are made of is QC'ed to a certain overall consistency of thickness.

 

[hrlincoln]

Yeah, there might be something to this...the photo below shows three 700 short action firing pins. The one on the left is the one in this rifle...you can plainly see that it has a different shape than the one on the right. I will have to go back and review Tony Boyer's book as he has a pretty extensive section regarding the shape of the firing pin tip. I think I will swap out the one I am using now for the more favorable looking one and see what happens.

+1 on Tony's book. Type A on page 58 closely resembles your choice on the right and would be a good first step.

 

[msinc]

Yes sir, that's what I was thinking.

 

[dkhunt14]

Funny you mention this...I have had this rifle for several years and just rebarreled it. Same caliber, better barrel. back when primers were a little hard to get the local gunshop had some Remington 6 1/2's. They were just all that was available at the time and so I tried them. It pierced absolutely every one of them and I told the guy that he might want to pull them or at least make sure he tells people they are not really for 223/5.56 cartridges. He said,"you are the only one complaining" and I dismissed it as guys that were just glad to have primers at the time. Because of this incident, I know that 6 1/2's are thinner, but I did not know that magnums and BR primers were thicker...I was always told and read that BR primers were a more consistent thickness because the sheet they are made of is QC'ed to a certain overall consistency of thickness.

I believe it is just some of the small rifle primers with the thicker cup. I think CCI BR4 and 450, Fed 205m and Rem. 7 1/2 have the thicker cup. Goggle primer thickness chart. I also think the Br4 has a harder brass alloy. Matt

 

[swd]

Bush it, anything else is just a band aid at this point.

 

[dkhunt14]

Yeah, there might be something to this...the photo below shows three 700 short action firing pins. The one on the left is the one in this rifle...you can plainly see that it has a different shape than the one on the right. I will have to go back and review Tony Boyer's book as he has a pretty extensive section regarding the shape of the firing pin tip. I think I will swap out the one I am using now for the more favorable looking one and see what happens.



Edit: I should add that none of these strikers have been modified in any way...they are as received from the factory.

In the picture it looks like the one on the left is a thinner firing pin. Like a small rifle primer verses large. Matt

 

[powderbrake]

Send it to Gre-tan and have it bushed. He will reduce the firing pin diameter, and the bush will fully support the front of the firing pin so it will stay centered. I had my Rem 700 done by him when I got some firecutting from faulty primers. It looks great and shoots great now.

 

[msinc]

In the picture it looks like the one on the left is a thinner firing pin. Like a small rifle primer verses large. Matt

Yep, I just miked them, but they are not different by much. I think it might be an optical thing going on because I had to arrange them in a kind of circle to get the tips in the photo. The one on the left mikes .0735" the middle and right mike in at .075". They just do go in the bolt hole of this bolt. I don't have plug gauges to get dead on in a hole that small.

Edit: it's a heck of an illusion too...I just took another look at the picture and held calipers to the screen...doing that there seems to be a way bigger difference than what they mike.

 

[timeout]

Bush it and use a .062" firing pin. I'm with Carlsbad, once you go bush, you'll never go back.

 

[carlsbad]

Bush it and use a .062" firing pin. I'm with Carlsbad, once you go bush, you'll never go back.

I measured a lot of .062 firing pins and they were generally .059 so I bush to .062 and grind firing pins to .0595 to .060. --Jerry

 

[msinc]

I measured a lot of .062 firing pins and they were generally .059 so I bush to .062 and grind firing pins to .0595 to .060. --Jerry

Have you ever had any problems so far with the striker trying to drag or seize or otherwise not working properly with those dimensions???? Is there a chance of it if you were to go with .001" for a clearance??? I guess you don't really need it that tight with a bushing because you now have constant guidance of the striker.

 

[carlsbad]

those dimensions are plenty tight. like discussed above, the clearance isn't as important as the smaller diameter. I already tightened up the clearance probably more than many would recommend. --Jerry

PS no problems with dragging. Everything is centered and colinear.

 

[carlsbad]

Alex,
One gunsmith that works a lot on bolts recommends taking the handle off and doing the work in a collet. If you're going to adjust the timing anyway, that makes sense. --Jerry

 

[gotcha]

You think he recommends it for quality of work or speed and ease? No matter how you do it, if the bolts indicated in properly and the pin doesnt bind your good!

Sure wou8ld be interested in your opinion on firing pin tip SHAPE and its potential effect on ignition and potential of pierced primers. ???????????????

 

[carlsbad]

Half round is good. Shape is not critical. Size is the governing parameter. I have NEVER had a pierced primer with a .062 nominal firing pin. I'll stand by for Alex's thoughts. --Jerry

 

[carlsbad]

Here are the images I tried to upload earlier today. This is a magnum boltface I bushed last month and a cartridge fired from it.