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Gunsmithing Help me troubleshoot my HS Precision DBM?

BigBrother

Sergeant
Full Member
Minuteman
Feb 27, 2007
687
5
New England
Hey all. I have an HS Precision DBM/bottom metal kit on my Remington 700P, and was looking for some help with feeding/extracting issues.

I know many prefer Badger and other makes, but I like the HS P's ergonomics and looks, and I know plenty of people have them operating with no problems, so I'd really like to get this one working correctly. It's also possible it's not the kit or mags at all...

Here's the issue:
In slow dry fire exercises with inert rounds, both of my mags load and cycle without much of a problem. If they do exhibit issues, it's pretty infrequent.

But at a recent match, where, for the first time, I had to cycle the bolt rapidly, I ran into two issues:

1. A new round would get jammed partway through the loading process. When I'd eject and examine it, the bullet itself would have little nicks/burrs in it, roughly in the middle. This would happen sometimes in my slowfire exercises too, and I'd notice the same nicks/burrs on my inert rounds after it would occur. But it seemed to happen a lot more at speed.

2. A round simply would fail to strip off the mag and chamber. I'd push the bolt forward and it would cleanly close, basically on empty air! Hadn't had that happen on the dry fire exercises.

<span style="text-decoration: line-through">I'd attach pics but don't have any handy at the moment.</span> EDIT - see below for pics.

I'd really appreciate your help with this!

Oh, and as a final note- I don't *suspect* it's one individual mag versus another, as I vaguely recall both had the half-loading/nicking issues during my dryfire exercises.

Thanks all!!
 
Re: Help me troubleshoot my HS Precision DBM?

New the H-S Precision DBM came with two washers. Sometimes you have to one or two to get it to feed right. Let me find my instructions that came with the DBM and I'll get back to you on their use.

Bob
 
Re: Help me troubleshoot my HS Precision DBM?

If it is riding over the top of the round, then it sounds like the round is not sitting high enough. you can either bend the lips of the magazine to let the round ride higher. But this can only be done within a small range. HS makes a tool to help you get the feed lip angles correct depending on the cartridge. Does the magazine seat fully and click into the DBM? I ended up trimming a little bit off the top/front of the magazine because it rubbed against the bottom of the action. This allowed my mag to seat fully and ride higher: works perfect now. This problem happened with two Surgeon actions.
 
Re: Help me troubleshoot my HS Precision DBM?

Lots of ways to tweak this. I would start with thin washers before I tried to modify the inlet or bend mag feed lips. Sounds like the front of the mag needs to come down and/or the rear raised. Start with an empty mag and see if the feed lips are roughly parallel to the bottom of the bolt. It is good to be as close as possible without touching. As you are adjusting position use dummy rounds or live ammo in a safe fashion.

Play with things. I have never found one I can't make work; some drop in and work perfect; some need a little elbow grease.

It is possible (but less likely) that the spring/follower are dirty or require tweakage.

On edit, check your COAL. If the tip of a projo touches the front of the mag this can impact feeding because the rounds can get presented in the nose-dive position.
Good Luck!
 
Re: Help me troubleshoot my HS Precision DBM?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: lvcatfish</div><div class="ubbcode-body">On edit, check your COAL. If the tip of a projo touches the front of the mag this can impact feeding because the rounds can get presented in the nose-dive position.
Good Luck! </div></div>

First off, thanks for the help everyone! Secondly, LV, care to explain this a bit more? Not familiar with the term.

Thanks all and keep em coming!
 
Re: Help me troubleshoot my HS Precision DBM?

If your coal of the round ( length of the rnd onlya problem when reloading) is too you can have the tip of the bullet catch under the lip of the feed ramp. This happens because the rnd does not always feed straight sometimes they are at a downward angle( tip low base high)

make sense?
 
Re: Help me troubleshoot my HS Precision DBM?

Previous post explains this well.
COAL = Cartridge Over All Length

You need a little space between the tips of the projectiles (projos) and the front of the mag. If a projo touches it can drag and present rounds nose down which is not conducive to good feeding. Where this drag is bad enough the spring and follower may not be able to overcome it as the remaining rounds start to jam the mag. Rounds should be presented tipping slightly up but not too much.

This is a little tough to explain to someone, but after you play with it it should become more obvious. I used to tolerate sloppy feeding but not since I sat down and played around to figure things out. I now tweak all of my sticks for optimal feeding. It is not hard but it does take patience to do this well.
 
Re: Help me troubleshoot my HS Precision DBM?

Okay, so before I start sanding the stock or using washers, I finally got to taking some shots with the magazine and dummy rounds in and wanted to post. You pros should probably be able to take one look at the angle and height and determine how it's off. So, here goes!

Empty chamber:

img1920o.jpg



img1909v.jpg



img1915t.jpg



img1910u.jpg



img1912fa.jpg



Thanks!!
 
Re: Help me troubleshoot my HS Precision DBM?

It looks to me that neither the magazine nor the cartridge are sitting high enough. You need to adjust your stock inlet to get that magazine higher. Take it to a gunsmith experienced with installing HS DBMs.
 
Re: Help me troubleshoot my HS Precision DBM?

The installed height of your magazine/floor metal is too low. The face of the bolt is getting a very small purchase on the case rim. When the cartridge attempts to ride the feed ramp into the breech/chamber the angle becomes too extreme and the bottom of the bolt slips off the case rim and then crashes into the body of the case. A stoppage is the result. You have to get the feed lips of the magazine higher, to where they just stay off the bottom of the bolt when cycled. The magazine is a centerfeed design so it should run like a raped ape when done properly.

This is what I've learned after installing a lot of these over the years.

Good luck.
 
Re: Help me troubleshoot my HS Precision DBM?

I had this problem with a badger M5 I picked up. When installed in the stock with provided pillars it was hard to seat the mag and would do what yours is doing. I tried another one of my AI mags and it worked fine. After comparing the two I discovered the new mags feed lips needed to be spread a bit and after that it works like a charm.

HS sells a feedlip tool for these magazines.
 
Re: Help me troubleshoot my HS Precision DBM?

Agree with others above. Feed lips look to be parallel to bolt/action. Hard to tell from pics but it does look like the bottom metal/mags are sitting too low down. If you still have the o ring at the bottom of the mag rim then remove it and see if the mag seats any higher.

I always try to tweak my bottom metal position as much as possible to achieve better feeding. I bend feed lips as a last resort. I share my mags between various rifles and mag adjustments that work good in one might not go at all if used in another rifle.

If you are feeling ambitious then polishing the feed ramp with a dremel wheel and mild abrasive paste never hurts feeding... Just be sure to clean up the mess from the action when you're finished. Check for sharp edges or burrs on front of the mag. I sometimes file or relieve a radius on the front edge of the mag so things slide over easier.

Also note that some stocks require a minor relief cut so that the HS bottom metal mag release button does not kiss the inside of stock in front of the trigger area. How easy do your mags release?

You can do this yourself but it does require patience. If you aren't willing to spend an afternoon playing with it then it may be best to send it off.
Good luck either way.
 
Re: Help me troubleshoot my HS Precision DBM?

Thanks a lot for all the advice everyone. LV - the mag release is nice and smooth, no problems there.

It seems like the two pieces of advice here are generally the lips and the height.

I'm going to go for height first - for those who know, is there a risk of going *too* high? I'll be using sandpaper here so it's not like I'll be taking inches off at a time
smile.gif
, but I am curious.

Even if I go too high I can use the included washers to lower it back down a bit, but now that I'm getting into this I'm just interested from an operational perspective - what range do I have to play with here with regard to height?

Thanks and happy M Day!
 
Re: Help me troubleshoot my HS Precision DBM?

Hmm, interesting - the removal of the composite material above the latch housing they mention might be the problem. I had removed enough for everything to fit and the latch release to work, but there's definitely stock material left between the DBM and the lighter gray part of the stock. Have a look - these are shots from above and below:

photo3ym.jpg


photo2im.jpg


Could that be the problem? Should I really sand it all the way down?

 
Re: Help me troubleshoot my HS Precision DBM?

Looks like you need to take off from the bottom of the stock. If your not that comfortable doing it, take it to a good gunsmith. It will not cost too much, and if he messes up, he gets to pay for a new stock, not you. But it only needs by the looks is a few thousanths to get the clip to the proper height.
 
Re: Help me troubleshoot my HS Precision DBM?

Looks like you might be touching where the mag release protrudes. Put a piece of clay or playdough there and insert the bottom metal firmly. If you can see the fiberglass anywhere through the clay then you are touching there.

Also the relief cut is normally along the back part of the magwell area and not literally at the front part of the trigger cutout like my prior post may have suggested.

On some HSP stocks the pillars protrude out past the general depth of the bottom metal inlet. Carefully removing some of this protrusion will seat the bottom metal deeper thus making the mags sit higher up close to the bottom of the bolt. If you need to do this, try to keep the feed lips parallel to the bolt/action bottom. Pointing nose up very slightly may improve feeding also.
 
Re: Help me troubleshoot my HS Precision DBM?

Look at the pic you need to remove material from the area under the latch. I use a mill and go about .125 deep. You do not need to cut into the aluminum bedding block to clear the release. .125 will leave you just shy of the block.

HS2.jpg
 
Re: Help me troubleshoot my HS Precision DBM?

Ok, so I just took a look again-

It appears the height is being dictated by where the bottom metal is hitting the pillars, not the area around the latch. There is plenty of clearance there - I could fit half a finger width in the gap, and the latch works no problem. It is definitely the pillar contact that is setting the height.

At this point I may take it to a smith. My trusty sandpaper my not be enough for this job
smile.gif
.
 
Re: Help me troubleshoot my HS Precision DBM?

If the bottom metal is sitting flush with the bottom of the stock like in the pic the bottom metal doesn't and shouldn't need to go any deeper. The problem is with the mag feed lips or there is some other issue that just can't be seen through the internet.

You push the bottom metal up into the stock further then it should be you will have other issues.

HS2-1.jpg


HS1.jpg
 
Re: Help me troubleshoot my HS Precision DBM?

Well fuck.

Mine sits nice and flush. Maybe I'll call HS-P and see what they think - I can't see how the lips would lead to problems like the bolt entirely missing a round.

Can someone on here perhaps take pics like mine, with a round in the mag, from various angles so I can see their height, how close they are to the ramp, etc.?

Thanks a lot everyone - I really appreciate the continued help!
 
Re: Help me troubleshoot my HS Precision DBM?

If the lips are keeping the round too low or the front of the lips are keeping the tip of the round too low the bolt can miss the round or push the round low into the bottom of the feed ramp stopping forward movement causing the bolt to ride up and over the back of the cartridge when the bolt is run fast.

The springs in the mag could also be weak. Both of these or a combo of them can cause just what you are experiencing.
 
Re: Help me troubleshoot my HS Precision DBM?

Got it. I just called HSP and they had me take measurements of the lip distance at the front and rear with my micrometer. Front (facing the muzzle) was about 0.412", rear was 0.427". They said this was within spec. Hate or LV, what distance do you get?
 
Re: Help me troubleshoot my HS Precision DBM?

Ok, I guess I'll open the front a bit then. I have a sneaking suspicion that alone won't solve it, but I have a date with a local smith anyway... we'll see.

Don't know if it'll indicate anything to you, but here are some shots of the mag...

img1939f.jpg


img1940f.jpg


img1941s.jpg


img1943k.jpg
 
Re: Help me troubleshoot my HS Precision DBM?

Also take one of the mags apart and stretch the spring and see if this also helps. If it does this would indicated the springs are weak. Stretching them may help for a little while but it's not a permanent fix.