Thread: 175 grain 7mm rem mag won't load

I recently acquired a Remington 700 bdl in 7mm rem mag. The gun seems to have a very tight chamber but it will cycle factory loads in lighter grains (sometimes still a little stiff). I was given a lee loader Hornady brass and Hornady 175 grain (core lock?) and after making my first round it gets pulled out of the magazine fine but it jams the gun and stuck in the barrel. After removing it I made a dummy round to see what's going on (no powder or primer) and it did the same thing, this one actually collapsed a little behind behind the neck. Everything measures out ok, what am not doing? Thanks for all the help! I forgot to mention that the brass cycles fine before the bullet is inserted, and the bullet diameter is correct.

Sounds like the OAL (overall length) is too long for that bullet. Not all bullets have the same profile and many of the heavier ones are larger further forward than the lighter ones. If that's the case here the bullet is probably being pushed against the rifling in the barrel.
Do you have a Hornady manual? It should list the OAL for use with that bullet? (I have one, but it's not handy at the moment) I highly recommend that you get that info. Make sure you are using an appropriate powder and weight of powder for that exact bullet. By exact, I mean Hornady 175gr, not Speer, Sierra or any other.
Why the bullet is not just pushed back into the case baffles me, but that's not a good thing to have happen either!
Using a dummy round keep seating the bullet deeper until it chambers. Measure the OAL then, and seat the bullet a little deeper so it has a little "jump" before it hits the end of the rifling. Unless something is completely wonky with your gun's chamber, you should be able to move the bullet into the case some and not create a problem.
But, getting the info from Hornady would be where I would go first.
PM me if you can't easily find that info. I'll dig out my Hornady book and see if I can be of better help.

I am using RL-22 for the powder. I thought the OAL would be my problem, but again I looked at the SAAMI specs and didn't want to go to far down. I am ordering the Hornady book, because the ABC's of Reloading book I have doesn't cover actual cartridges is just kind of a guideline book. So I guess I will find out when the book comes in what they reccomend. I do know that the bullet diameter on the Hornady 175 is significantly larger, further out (more of a round nose), than the lighter grain speer which is more of a spitzer style. Thanks for the info, I will order the book, and try backing the bullet down.
Thanks!

Hornady 175 grain (core lock?)

Core lock would imply Remington, are you unsure of what bullet you have ?

the bullet diameter on the Hornady 175 is significantly larger

The bullet diameter should be .284"

The max COL with a 175gr bullet normally does not exceed 3.290".

The max case length is 2.50". so the cases should be trimmed to 2.490-2.495".

and try backing the bullet down.

Reducing the COL will increase the pressure.

I apologize it was late and I wasn't looking at the box, it is Hornady Inter-Lock. By "significantly larger diameter" I am trying to reference the "taper" when compared to a lighter grain spitzer as opposed to larger round nose. The bullet diameter is .284. I apologize about my lack of correct terminology, I am kind of wading my way through this as its all new to me. Case length is under 2.5 inches and I had a OAL on two different cartridges that both jammed, one was 83mm and the other was just shy of the 3.290 inches.
Thanks again!

Originally Posted by jib

The bullet diameter should be .284"
Reducing the COL will increase the pressure.

The bullet diameter is .284" but a round nose bullet usually carries a larger diameter farther forward of the case mouth than a spitzer (or pointed) bullet. Also speaking in generalities, a heavier bullet is longer and is "thicker" farther out than a lighter one.
Reducing OAL generally does increase pressure, but if it's getting the bullet off of the lands of the rifling it will actually lower pressures.

The Hornady book lists an OAL (or COL) of 3.260" for the 175gr Spire Point bullet. Below that in small print it says, "These Data may also be used with the 7mm 175gr RN bullet, though overall length may vary". Sounds to me as though they know there will be length issues with the RN bullet in this cartridge.
I'd start at 3.260" and see if that works. I'd recommend starting at the lower end. My book doesn't show RL22. (it's kinda old) May need to do some additional research for that.

Kibs45, what is the case length after sizing ? How many times have these cases been loaded ?

Brand new brass, neck sized only. The RL-22 is a 53-64ish grain load in this application.

Brand new brass, neck sized only.

Will the neck sized case chamber in the firearm without a bullet ? Do have a instrument to accurately determine length ? I trim new brass after sizing to a recommended length.

The RL-22 is a 53-64ish grain load in this application.

My data shows 175gr Hornady #2850 SP COL 3.290" and 175gr #2855 RN COL 3.280"
RL-22 start 55.9gr
RL-22 max. 63.4gr

I would not fire any loads until these issues are resolved.

Trust me it's not going to be fired until this all gets sorted out. I should get another chance to look at it this afternoon. I will take full measurement etc. Thanks again.

You may want to take a look at this: Determining Bullet Seating Depth | The Reloading Press


elsie

Originally Posted by kibs45

Brand new brass, neck sized only. The RL-22 is a 53-64ish grain load in this application.

I've found that even brand new brass should be fully resized & trimmed before firing... After the first firing, its fire-formed to your chamber. My understanding is that's when its good to move to neck sizing/trim as needed.

HtH!

When you do get the case and bullet extracted, are there marks on the bullet from the barrel's lands and grooves?

82.5 mm oal length seems to be chambering. But yes the bullets are coming out marked. 82.5 is chambering but it is pulling the bullet out further when cycling, so I may shorten it just a touch more. The cases are just shy of 2.5 inches, and yes the brass alone chambers fine after neck sizing. The problem is definitely in the bullet seating depth.

I have to ask you if there is any way that they may have given you the wrong bullet. They should be .284? I see you have already been asked this question which would be a first question. My advise would be to make a dummy round. Cover the bullet with a black marker and chamber it and close the bolt thus seating the bullet by cam force. That way you can find your lands length. Then move it deeper in the casing afterwards. I know other people have told you to do pretty well the same thing this is just another angle.

When I get a new type of bullet or a new gun, I keep experimenting until the lands just barely mark the bullet. Then I back off .020. I record that OAL and stick with it. If course I'm measuring OAL all the time with a mic. A very good dial indicator caliper might be close enough? Others can speak to that. I use an outside mic.

I also have a "go/no go" for each of my calibers. That was actually the straw which broke the camel's back and caused me to start going to fewer calibers so I could have lots of ammo for each gun, and fewer tools, powders, primers, etc. I still have as many guns, just fewer calibers.

Gentlemen:
The way you guys jump on a problem is inspiring! I have not tried it yet but my reloading bench is almost ready to go.
Glad to have all of you on my side.
Paul

Another possibility is that you are over-crimping and deforming the shoulder.

Since the brass fits before being loaded and you are under the book OAL, I'd guess this is a strong possibility.

edit - I missed that the bullets are getting marked - probably an OAL issue.

Originally Posted by toolfan

Another possibility is that you are over-crimping and deforming the shoulder.

Since the brass fits before being loaded and you are under the book OAL, I'd guess this is a strong possibility.

edit - I missed that the bullets are getting marked - probably an OAL issue.

Yes, but that's something good for him to know. Most people I know don't measure or resize cases to uniform length, and therefore the crimps are uneven. Some are crimped too much and some not enough no matter die adjustment.

Brand New Brass should always be full length sized and then measured and shortened to the OAL of the shortest in the batch. Then fire forming with a moderate charge. Now, you can do the neck sizing and make sure you mark these as being for that rifle in particular.

Other than those items I can't add much to what has already been said.