Modifying 10ML-II BP

[ET1]

My first statement is that I’m not recommending anyone to just simply do what I’m about to share. To go this route is a personal choice to achieve a more efficient ignition system.

My 10ML-II is an early model before accutrigger model surfaced with serial #M007915.
It came with a plastic ramrod that was affectionately known as the noodle rod. I replaced it with a solid aluminum rod that made a night and day difference for loading. Then the mention by another came along that he recessed his vent liner deeper into his BP to increase the ignition property of his system. As tempting as it was to immediately go this route I first decided to study the savage BP more carefully and read up on powder ignition requirements. Once I felt confident with what I learned and knowing that I would alter the pressure exposure to the primer from returning bore pressure somewhat I decided to proceed with this modification.

Before I proceed with the modification I should mention that after the modification I did produce some blow back where I had to alter the head spacing (bolt to BP fit-up) to eliminate this blow back condition.
The original dimension used by the other individual was 3/8” wide and .800” deep. I opted for a less aggressive dimension and went with 5/16” wide and .625” deep recess. Yes I would now need to alter the 3/8” head dimension of the vent liner. No problem as I make (drill) my own vents using a screw that has more hardness. To reduce the head diameter is no big deal. Also keep in mind is the angle of the head of the vent screw. Here I used a 5/16” cobalt drill that had a tip ground 82-degrees to accommodate a proper seating fit for the vent screw.

Now this Mod for the BP was done in a drill press so it doesn’t require a lot of machinery.
This thread was not intended to promote or display any skills or smarts. It was intended to be educational or an interesting read. This recess mod was done over 5-years ago with no regrets what so ever. For my intended purpose it has been a benefit.

Setup for Drilling BP Recess.jpgBP Machined.jpg



Ed

[Gerald]

Why? If it isn't broke.... you know the rest.

[MikePal]

Sounds like you've found a working solution to a problem Cecil (PR Bullets) had with the earlier Savages. He doesn't specify what his fix is for the head spacing, but he'll fix it for you for $75 if you don't feel you have the skill set.

Savage 10 ML II Single Hole Vent Liners

The hole in the factory Savage vent liner measures .0305". By experimenting with a variety of breech plugs utilizing vent liner holes between .0285" and .035", we have found that there is a 'sweet spot' for the vent hole size and that is .033". We also determined that a step-hole offers more consistent results than the results achieved by using a one sized through hole. In other words, looking from the primer side, our vent liner hole is one size for the first .120" of depth and then steps down to .033" diameter for the balance. This step-hole acts as a sort of funnel and an expansion chamber all at once; getting more flame to the powder while reducing the pressure from the primer.

Just like our bullets, these vent liners are hand made one at a time for consistent results; shot after shot.
Priced at $ 4.95 each, add them to you next bullet order and they will be shipped FREE.
This is the 2006 article we posted on "headspaceing the Savage breech plug"; for interest sake.

Things that don't work properly drive me crazy. Savage 10MLII breech plugs are not headspaced from the factory. Every time I fire the Savage, I end up with a 209 that looks like the one on the left. The back pressure through the vent liner blows the primer back out of the battery cup. This jams the lip of the battery cup in the front of the extractor groove and the primer in the face of the bolt. To remove the 209, I either need a screwdriver to pick it out or a pair of pliers to pull it out. Or I can re the bolt, dry fire the gun and hope the blow from the firing pin pushes the primer back into the battery cup so I can remove the 209 with my fingers.

The last day I could not get the primer out of my bolt at the range was also the last day I ever had this problem. Leaving the range totally disgusted, I vowed to solve the problem or scrap the gun completely. Several days of mulling and tweaking yielded the solution.

HEADSPACING THE BREECH PLUG CURES THE PROBLEM FOREVER. REMOVE THE 209 WITH YOUR FINGERS. TOTALLY SEALS THE SAVAGE TO MAKE IT EVEN CLEANER. ADDED SAFETY BY ELIMINATING ALL BLOWBACK.

We need your Savage barreled action only. Turn around time is less than two weeks.
A bargain at only $75.00

[ET1]

Gerald

How about settle for what you get or strive for better.
If you’re happy with what you get then you should stay with it.

MikePal

Head Spacing is basically loosening the Savage barrel nut, screw barrel in a little further until BP is almost contacting the bolt and retighten barrel nut. This forces the bolt to seat primer a little deeper into BP. What does happen here is that open sight alignment is off centered. There are a few different ways to correct this but not without proper machinery.

My personal made vents start at .0315” and I will replace them when a .035” pin gauge passes through them.
First off I’m not in full agreement with his explanation with vent orifice principle. Yes his vent design will allow more thermal energy passage from the primer to powder but will also allow more back pressure from the bore to return. Vent liner orifice works in both directions.
With his approach of vent liner orifice by decreasing the passage length of restriction should also induce faster wear of vent liner orifice depending on the grade of steel. My vent liners only have a small chamfer for funneling and are made of Grade12 steel. By recessing the BP restricting the space between orifice and primer I’m generating more pressurized thermal energy from primer with less heat loss from absorption of surrounding steel before reaching main powder charge.

If you really study about powder ignition in actuality it is not all about the flame.
Powder has to absorb heat to reach a temp of what I call flash point in order to burn.
This is how burn rates are controlled by deterrents added to powder. Of course granular shape and size plays a role also for rate of heat absorption. I know a lot of people believe the flame does all the work but that’s not case.

Picture is comparrison of Savage Vent and Homemade vent.

Vent liner Reproduction.jpg


Ed

[Exo200]

Enjoying these savage ML thread's as I just received mine a couple day's ago! Don't have much to contribute but I am like a sponge right now soaking it all in! I'll have to check back As of tomorrow I'll be gone for 5 day's!
Thank's guy's

[delmer]

I've been using the vent liners that Cecil Epps produces for a while now. Haven't really noticed any difference between them and the factory Savage as far as ignition or blow back are concerned. Just happened that I included them with a bullet order because they were shipped for free, and I knew that I would need some in the future.

[Big Jack]

I sent one of my Savage 10ML to Cecil to have the magic done. Quite a list of things actually.

Had bedded with additional pillar installed

Head spaced breach plug

Barrel crown

etc, etc

When I got it back it shot well but I noticed blow back down the side of the primer and erosion. Talked to Cecil and although he couldn`t see how the work he had done would have caused this, he sent me one of their new SS breach plugs to try on his dime. I put it together and went to range.

The result was a shrinking of group size from 3 inches at 200 yards to just over an inch....

Quite happy with that and really never had much of an issue with miss fires to begin with and that didn`t change.

Ed`s change above will likely go a long way to helping with misfires.

I have found magnum sub bases can also assist with this.

Also Sabots that are too loose cause this condition as well.

[ET1]

Big Jack

By having what you done to your 10ML-II you have unlocked it’s potential capability.
I too have basically done the same and have enjoyed one shot, one kill results. Bullet placement and knowing its responsive reaction to the velocity you are employing is a key element.

For some reason I never had good results with Sub Bases even though I’ve had good results with some loads using HPH-24 sabots.
I agree loose loads can add to ignition problems especially with smokeless powder.

Everyone wants and expects the best off the shelf for the money they spend. Expecting this from mass produced products is only a desire. In most cases you have to go that extra step to acquire the best a particular product can offer. If you are content with what you get off the shelf then enjoy. If not then some homework and research can unlock the real potential of a product.


Ed

[Final Flight]

I've got a question guys.....I've only been an owner of my 10ml-11 for a couple months now, and until the snow departs I'm unable to establish my load preference. I have only shot 3 groupings so far, and I already know it is a 2 inch gun at 100 yards without alot of tinkering. My goal is to have a 3 inch gun at 200 yards(my maximum distance I will be hunting with). Will I need to do more than establish my "pet load" to achieve this accuracy? Thanks for all your replies. John.

[ET1]

Final Flight

Your post doesn’t have much info to go on for an evaluation of what you have.
The 10ml-II has its own learning curve for properly setting it up.
Hope you don’t mind answering some questions.

1) When you first got your 10ML-II did you really clean the bore to remove the preservative?
2) What is your load for sabot, powder and bullet?
3) What is your load resistance?
4) What waiting time are you using between shots for barrel cooling?
5) Is your barrel free floating or contacting the stock on one side?
6) Is your stock synthetic or laminate wood?

These are just a few questions to get a better idea of what you got to start with.

Ed