Bolt Bushing Reduces SD!

I in my wildest dreams did not think that Bolt Bushing could help with SD (standard deviation). In my mind it helps immensely with harmonics but not SD. I was wrong however. It seams I have had an overwhelming number of customers tell me that after they had their bolt bushed, they saw a drop in SD. If you do not know what some of the other benefits are to bolt bushing you should check out my other blog post called  What Does Bolt Bushing Acomplish. Below are two testimonies of just how much Bolt Bushing has helped some of my customers.


Sam has a custom Mosin that he could hardly even get to a mild load without blowing primers. His bolt was getting filled with soot and primers fragments too. So he sent me his bolt and I took the hole from a 0.100in and firing pin that was .091 to a much smaller .069 and made the bolt match to that size with proper clearance. Here are his results. Sam tells me his SD dropped significantly too.


Big shout out to Grimstod Desh for all the work on my bolt. Shoots better than ever. 5@200. I’m as happy as a possum on a big green tractor eating grapes.

5 shots at 200y

Sam had to revisit all his loads because of all the new room he had in his rifle now and here is where he finished. Primers are still not flat and now that he does not have any flow around the firing pin he could gain a great deal of MV and accuracy.

“I’m shooting 55gr of bl-c2 under a 168gr bthp and getting 3011 fps average.”



Success Story #2



Another Customer Grindl who takes his Mosin to F-Class matches and even the SWN.

I began having issues with my competition rifle doing weird things . Hang-fires , Non-fire after pulling the trigger and the gun not firing , but the primer dented . And worst of all , it was starting to effect my scoring negatively at a rapid rate .

I contacted Grimstod and sent him my bolt and a extra firing pin to match up , so I’d have a back-up . Turn around time was about six days total and I’ve seen a great improvement in overall performance since the bolt was re-bushed and the F/P turned down .
And like most “F” shooters , I track my scores , and percentages very closely . Since having the bolt done ,on average , I’ve dropped from three “8’s , to one , and my 9’s count has also dropped three or four a string . That means I’ve gained four to six points a string of twenty shots , and over-all my scores have gone up from low 180’s to mid 190’s . And makes this M-N competitive .

So if you’re having firing issues , cratered primers , hang-fires or any of those gremlins and you think the bolt is the problem . Contact Grimstod ….I have been very pleased with the job he did on my bolt / Firing Pin-(s) , and I highly recommend his work . And by way of qualifying my recommendation to any of you guys , I’m a retired master tool & die builder , so I think I can tell good work when I see it . And Grim does good work .



Gene recently send me this update.

“Thought I’d send you a pic of  the results of your work . 100 rounds fired on my 600 yd comp load , which you said I could push harder . I did boost it . From 48.6gr to 53.4gr. Can now shoot the high node & easily 50% more accurate .”


Picture Gene took at the 2018 SWN



First Barrel Chambered!

I did the first chambering job. Reamer worked great. It seams to cut pretty evenly. I know that no reamer ever cuts perfectly uniformly on all flutes, but this one did very good. Took me about 1hr to do it. Dialing in the barrel was not as hard as I thought it would be. Perhaps I am getting faster at this. The finished chamber looks quite smooth. No scratches or chatter marks. Having flood coolant is such a joy and makes chip control a lot easier.

Sadly I cannot exactly finish headspacing this until the resize reamer arrives. That will be easy as this is a Savage. Seating die is next.

Bedding Pillars

If you ever wondered what bedding pillars here is a quick insight. When you torque down on your action screws the stock is compressed between the bottom metal and the receiver. Tight is usually good but this can sometimes crack your stock. If you have ever been at the range and suddenly you groups opened up it may be because you stock has cracked on the inside. You will not be able to see it but it is happening and causing more damage with each shot.

Bedding pillars act like, well pillars. Pretty simple. They prevent the action from squishing the stock. They are always put into a stock in conjunction with glass or epoxy bedding compounds. The bedding compound spreads out the seating force of the receiver and gives you more surface area to grip the stock while the pillar make for a solid surface that you action can be touched down to consistently each and every time.


With the Savage Axis bedding pillars are especially beneficial. The Axis does not have an integral recoil lug and every time you shoot it the torque from the bullet taking on spin from the rifling twists the action in the stock and mostly against the action screws. Putting your action screws into bedding pillars helps give you a more solid foundation and repeatability from shot to shot. That translates into accuracy.

Some bedding tips. You want a song bond between the wood and the epoxy. Take a dremel and peck a bunch of spots into it to create this pattern. It really helps the union stay strong. Excuse the civil war joke. You will also have to open the hole a little for your bedding pillars.


Last thing to tell you are just some of the particulars of these bedding pillars. The forward on is .43in long and the rear one is 1in long. If your stock needs something different make sure you let me know. I sell these as an add on only with my action clip. They are $5 a set. I knurl them and the diameter is .375in or 3/8ths.


75% Magazine Catch Blanks

UPDATE: I now no longer offer the 75% Catch Blanks. However I have good news for those of you that are overseas. I now sell a new one that is completed and even anodized black. It is for sale now directly through Boyds own website. Here is a link.

These are for export out side the USA only. I produce these in limited quantities and they are 75% completed. They do not function in a Savage Axis with a wood stock until the end user has drilled a hole in it. In manufacturing these four operations are necessary to make them. I simply skip one of the four and thus you have a 3/4 or 75% completed part.

Its a very simple operation and just requires a drill press. I have even made a small pilot starter mark to center up your drill. Aluminum is a soft metal and no different to drill then hardwood. I recommend starting first with a .125in (1/8in) drill bit then finish with the .25 (1/4in) drill. Use a vice or clamp to hold the mag catch. You do not want it to spin on you because aluminum is very gummy and tends to stick to the drill bit. Also be sure to use a faster speed if your drill press allows and peck in small increments.

Warning. Remember that Boyds stocks do vary a lot. Maybe I should have written that like this, “A LOT!” You may have to do some dremel work, or file the clip edge depending on your stock. More than 95% of my customers have reported that they did not need to though.


What Does Bolt Bushing Accomplish?


There are three things that Bolt Bushing solves or improves greatly. I list them here with details and in the order of their importance.

  1. Easier bolt lift. This is the biggest reason for me. Because the firing pin and the unsupported part of the primer is reduced immensely you can also reduce the tension on the firing pin. This does many things. It makes opening the bolt much easier. With reduce effort in bolt lift you can better feel when cases start to get sticky in your chamber. I have also noticed that if a chamber is dirty I can feel this with a rifle with an already light bolt lift. With less effort on bolt lift cycling your bolt is faster too. This is possible because you have downsized your firing pin. Making it smaller means there is less for required to dimple the primer enough to start ignition.
  2. A more consistent ignition sequence. If your firing pin is off center in your bolt, and most of them are, your firing pin may sometimes strike the anvil, in the primer, between the legs. This means the firing pin must penetrate deeper into the primer before the ignition sequence starts. In turn this means your harmonics will be different ever time you pull the trigger. Now it is a small change but for those of you that are critical about accuracy and you need avery bit of accuracy you can squeeze out of your rifle, this is a big deal. Just like truing a rifle receiver, having a centered firing pin is important to accuracy. Also think of this too. If your firing pin strikes and pushes your cartridge into the chamber on its side, and not centered, it will cause the cartridge to be ever so slightly crocked in the chamber when it begins its ignition sequence.
  3. The elimination of cratered primers. This is why the vast majority do it though I believe it’s the least important. Bushing your bolt will forever eliminate cratered primers. You will have to work up hand loads from now on using primer flatness as your guid rather then primer cratering. For many shooters this means they can shoot faster, although this should not be the objective. For example I had a customer bring me a bolt once that would not shoot even a mild load without excessive cratering and even blanked primers. When I took his bolt apart it was filled with brass cups from primers. His firing pin was massively oversized and Bushing it fixed this allowing him to shot scolder to book max PSI levels.

Every shooter that is considering getting their bolt bushed is usually a hand loader. I have however had some customers that couldn’t get even factory loads to fire in their rifle without blanking primers, just because the hole was so oversized. If you are considering getting your firing pin and bolt bushed think and ask your self these questions.

  1. Is a faster and smoother bolt cycle important?
  2. Do I need to ring ever bit of accuracy out of my rifle that is possible?
  3. Is achieving the max safe PSI level of my chosen cartridge necessary?

Lastly you need to decide on a size. Most IBS gunsmiths set theirs at .062. I offer a verity of sizes and I recommend them depending on your intended use. If you are shooting strictly from boxed ammo and not hand loads then .068 is a good size. If you’r a reloader then .064-.066. For hand loaders, you know who you are, typically .062.

Last thing to decide is what clearance you want. Clearance is how much room the firing pin has to move through the bolt face. Most factory rifles have monstrous amounts. Like .005 and up. I however have never seen a factory off the shelf rifle with less then .006. Now having a ton of clearance is great if your are dumping mud into your action to impress your friends on your rifles reliability during a stress test on youtube, but for real life its not necessary. For hunters and PRS style shooting,  .002 is plenty and bench rest shooters usually get .0015 or even .001. It all depends on how clean you keep your gun.



A customer testimonial.

I have a Savage 12 .223 that I shoot with 90 VLDs. I was getting significant primer cratering so I decided to get the bolt bushed. After doing some research and learning of Grimstod’s reputation in this area, I decided to send it to him for the work. And because I don’t eject my brass, I asked him to plug the ejector hole while he was at it.

The service, communication, and workmanship he provided were second to none. No more cratering, and as for how well he filled the holes, I’ll let the photo below (not photoshopped) speak for itself.

Dave Rabin


Why we left out the ears.

There are three very good reasons committed the ears.
1. Cost, making the ears on the magazine catch requires 20% MORE material and a third setup in a CNC machine. A very complicated setup I might add. Also three additional tools that have to change and make the cuts. This adds to the COST a lot. This is why V3 Tactical sells theirs for $30 ea, and I can make them for 11.99.
2. Flexibility. Boyds stock very a lot, and about 5-10% of my customers have needed theirs modified to get the magazine to fit. It is not a problem with my QC of course. The HAAS CNC I use has a tolerance of .0002 over an inch that keeps my Magazine Catche tolerances supper tight. Its the Boyds stocks that vary so much. Omitting the ears made it a lot easier to fit these to a variety of inconsistent stocks.
3. Smooth functioning, I noticed from the get go that omitting the ears just made putting in the mag and removing it faster and smoother. Sometimes the snap on the mag gets hung up on the ears of Boyds plastic catch so for this reason I omitted them.

Savage Bolt Bushing

A resent bolt bushing job done for a customer. This is an after photo and some of the procedures . Bushing decreases the size of your firing pin and centers it, you can see a photo here at the bottom of this page of a brass primer before bushing and a nickle plated primer after bushing. It has been known to increase accuracy and prevent ruptured primers on hot days. Also virtually all bench rest shooters make their firing pin approx .062in which seams to give the best results.

First the pin is measured and also the original firing pin hole. This one was a whopping a large 0.074in and the firing pin was 0.0675. The bolt is reamed out and a bushing is pressed in with 4 tons press. Then the bushing is drilled for a smaller firing pin hole. The end result is an almost seamless face with not sign of the bushing at all.


Then the bolt face is trued up with the lugs and the bushing is shaved down flush.


Finally the firing pin itself is reduced to fit the hole to perfection then lapped to ensure absolute smoothness of travel. With the new and smaller firing pin and hole, less pressure is on the firing pin. The amount of force on the firing pin is reduced by more then 20%. Now the shooter can reduce firing pin spring tension, if he so desires, and get a much easier bolt lift.