What are the do's and don't of ramp massaging to get bullets to feed--chris

Take it slow. It is a lot easier to remove more metal than to try and put it back on.

Here's a few...

1. Make up some dummy rounds and use them to check feeding. DO NOT use live rounds.

2. If it is a controlled round feed mechanism, make sure the extractor has sufficient clearance under its claw to allow the rim of the cartridge case to easily pop-up under it...otherwise you may think you have an action rail problem when your extractor may truly be the main culprit. Also make sure there is a VERY small radius on the bottom edge of the face of the bolt...just enough to surely eliminate any burr that might otherwise cause a cartridge rim to hang-up when rising from the mag box into position behind the extractor.

3. Watch the angle of the round as the feeding fails. Sometimes the ramp angle at the front of the magazine/rear of the barrel is too steep and needs to be slightly reduced. Usually, the point to where the round is being misdirected is directly opposite the metal that needs to be smoothed, reduced, or removed. Doing this without removing metal vital to the support of the chambered round can sometimes be very tricky.

4. If the point of the round is hitting the top of the front plate of the magazine (bullet point is not raising high enough to clear the front of the magazine) the problem MAY be the follower.....sometimes slightly reducing the height of the rear half of the top of the follower will help there. It may also be a mag spring which is not adequately supporting the front of the follower...a stronger spring and/or a little spring leaf bending can sometimes do wonders.

5. Note, that NONE of the above involve widening the space between the rails of the action. That is a last resort, and seldom works out in the hands of amateurs who haven't gotten a good grasp of the spatial relationships involved in the movement of the cartridge from magazine to chamber.

6. Oft-times, the space between the top of the action rails is fine, it is a very, very little UNDERCUTTING of the rails which is needed, to allow the round(s) to be more securely held as they move forward. Do not do undercutting with a powered stone on the first dozen actions you modify. The stone, if in a Dremel tool or something similar, may cut too fast, and can easily slip to cut where you do not want it to. Do your work with a hand stone until you REALLY know what you are doing, even though it will take forever plus about a week to get it done... As a previous poster noted, it is a heck of a lot easier to remove steel than to replace it.

7. If you MUST widen the measurement between the tops of the action rails, do so from the FRONT of the magazine toward the back...widening back along the rails only just barely far enough to get reliable feeding. If you carry the widening too far back, you will have BIG PROBLEMS WITH CARTRIDGES NOT STYING IN THE BOX, WHICH MAY BE INCURABLE WITHOUT A LOT OF DISCREET WELDING-UP AND PROFESSIONAL HELP.

All in all, I recommend you NOT learn on the action of a good rifle you want to keep. Get a couple of beater actions of the same sort as your good action(s), and modify THEM to successfully feed the cartridge you have in mind. Then, if you fully grasp what needs to be done, proceed to very carefully do what is required with your good rifle.

Take care,

Alberta Canuck

as the A-Square round slides forward and goes up the ramp and starts into the chamber and is about to pop up under the extractor it gets caught up--the belt gets right to the step in the feed rail and then the round stops

the bullet hits the ridge in the chamber, that I believe is where the belt would stop the chambered round--

at first the brass was getting pretty marred up as the ramp was very steep--I have very carefully removed mat'l and checked the feeding numerous times to make sure I don't go to far--now I have problems with only the 1st and 3rd rounds--rounds 2,4 & 5 work almost everytime---so do I keep after that ramp or stop and send it to the smith--

it would seem chamfering that step in the chamber would alleviate the problem, but I get the feeling that this is hands off area--as don't ever touch it---

do I keep after the ramp or attack the feed rail--

if the step in the feed rail were cut back about an 1/8" to allow the round to pop up under the extractor it would seem all problems would be solved, but I'm not sure what cans of worms I'd open up, although it seems like it would be ok--

so to me it's the ramp or the step in the feed rail--it's funny that it's only those two rounds that get hung up every time--there's no burrs and everything seems to look ok--I polished the mag box and stoned the feed rails some, but why do some feed and some don't--I think that it may be the shape of the bullet that may be the biggest culprit, but all ammo should feed is the way I look at it---

keep the info coming---chris

OMFG! Chris youe've already gotten more info than I've ever seen on the net re: feeding! I love this place (and AC as of today!)
Thing is, your stucks are both coming from the same side, and the follower pushes from one side, so, it really sounds like a rail issue,
though so touchy it might be better left to a smith (unless you want to learn more than you want the gun).
AC, please say something (anything!) more about #6.
There's not a lot of info out there about feeding. I'm sure much of the reason is that it's an art; yet if knowers would post what they can, maybe we'd mess up enough actions to give them more biz!
How great would it be if all actions were proportionally the same as the k98 for any round you want....

I have given about all the info I feel safe in providing, regards action tinkering, as I cannot operate & see your rifle from here to diagnose exactly what is up...

However, I WILL do a little guessing. Correct me if and where I go wrong.

1. If it is an A-Square built rifle, I assume it feeds at last some ammo okay, or you would have sent it back long before now.

2. Regrdless who built your rifle, I would guess you are not using A-square factory ammo, but are trying to make it feed your own handloads?

So, the question is, have you tried slightly shortening the overall length of the loaded round...say .010" at time?

If the round is too long, it will sometimes catch on the forward edge of the cartridge belt recess, just inside, and at the top of, the chamber.

Also, bullet shape makes a difference in some rifles...ie. a 270 gr. round nose may feed fine, but a 270 gr. spire point may not. (This is, of course, just another problem of bullet length...spitzers are generally always longer than RN bullets of the same weight...so need to be seated deeper to pass the same curves enroute to the chamber...even though it will put their ogive farther away from the rifling and produce more bullet "jump".)

Having too long a round most often occurs when the handloader is a meticulous, accuracy-oriented guy. He uses some sott of bullet seating depth measuring device, then seats his bullets just in contact with, or just off of, the rifling. Because all factory hunting chambers are cut a little long (by reamer design), so you don't suffer a jam in Ugumbutuwuuwu, Darkest Mongolia, that can make the cartridge considerably longer than the spec for factory ammo. And, a longer cartridge has more sticking out there to wedge against some part of the action/chamber as the case makes the "hump" over the magazine-to-barrel feed ramp.

So, just as an experiment, rather than putz anymore with your action at this point why don't you try seating your bullets deeper about .010" at a time until the cartridge will make it past that corner, and see what you end up with?

If that doen't do it, then I'd suggest sitting down and moving the individual cases forward very little at a time and taking some digital photos of what's happening, so you can study the problem out.

After enough looking at it, quite often the solution will just pop right into one's head all of a sudden...maybe a day or two or even a week later.

I do NOT recommend chamfering the front of the belt recess in the chamber. If your rifle fails to put a round under the extractor when you chamber it, and that edge is chamfered too much, you could end up with a situation where a case with a sub-spec belt goes far enough into the chamber that the extractor won't pop over it as the bolt closes. Then you could have a hell of a jam.

One thing which possibly WOULD work, if the bullet nose is always catching in exactly the same place on the edge of the belt recess, is to cut a very small "notch" in the front of that recess edge, right where the bullet is hitting it. That could allow the bullet to clear that sharp edge, and still maintain the integrity of the recess as a "cartridge belt stop" all the rest of the way round the cartridge head. The possible down side of this approach is that with high pressure loads, ANY space in the chamber is likely to be filled with cartridge brass when the round is fired. You DO NOT want to end up with a fired case which has a funny little work-hardened wedge-shaped expanded portion just at the top front edge of the belt!!!

Be careful, though. I accept absolutely NO responsibility for how things work out on rifles I don't do myself. (And, I have been out of the commercial gunsmithing business for about 15 years now, and will NOT get back into it...)

Best wishes,

Alberta Canuck

first off I want to thank you AC for responding--at least you've provided some insight and I can make the decision to keep massaging things myself or not--

Rifle is a CZ that I bought used and if fed and shot fine for Jim Brockman, but he didn't use A-square ammo---

the A-square ammo is factory stuff of which I have 60 rounds ---the round nose of this ammo is the culprit I think--it is not too long either as they measure 3.512"

I have yet to reload any ammo for it yet, but have all the stuff--Barnes and NorthFork--and am about to make up some dummy loads to see what shakes or I may buy some Hornady stuff to see what happens also--

I haven't even shot the thing myself as I wanted to run these rounds thru it to see if there were issues--

thanks again for the tips--chris

IT IS THE A-SQUARE AMMO that is causing me fits--I decided to see if I could, by hand, just insert some NF and Barnes bullets into some once fired brass I just received off of ebay--I was able to and so no problems with these feeding and I even had the barnes stuff out to length 3.7+ and they fed--it's the very round nose that's the problem on the A-Square loads---so I either try and sell this stuff, keep massaging the ramp or cut the relief in the top of the belt stop in the chamber, send it to the smith and let him work it over--of take $260 worth of ammo and shoot it up for brass--I guess I could keep the lion loads and send the other's back--I may do that--we shall see--at least I have my answer to the prob--looks like I need to get to reloading--chris