My New 300 Whisper

[Gelandangan]

My rilfe (24inch 1in 8 MAB on Zastava MiniMauser action) finally arrived last friday... been pins and needles all friday and saturday ( can't sleep saturday night ).
Came Sunday morning, I raced to the range at 7 am.. have to wait till the range open on 9am. Sokay, chatting with other shooters around and showing off my NEW 300 Whisper gun ... receiving a lot of "you'll be sorry about the performance" advices.

Then 9am came. Setup my chrony, target, benchrest, etc takes 30 minutes.
Then the range opens.

I select one cartridge (220 gns woodleigh on 10gns ADI 2205 ) place the cartridge in the action.. pushing the bolt forward.. and push.. and PUSH.. AND PPUUSSHH !!!! can't get the cartridge into the chamber... AAARRRGGGHHH!!!

Shame faced , I try to retract the bolt , so I pull.. and I PULL , and after exerting a large force levering on my scope base, I managed to pull the unfired, unchambered cartridge out.

So I packed up and went home.

At home, out came the micrometer and measurement shows that my cartridge (made from 223 brass) has 0.332" neck and the chamber (measured with a lead cast) has 0.333". Theoritically the cartridge should fit cause the chamber is 1 thou larger bore than the cartridge. However, in practice it does not. Why? could it be because the temperature causes the brass to expand? It was 32c in the range last sunday.

Wondering if I should try to crimp the tip of the brass just a bit so it will chamber easier? or should I just try to polish my chamber neck a tad to free it?

Advices welcome.

Gelandangan

[DonT]

My first thought is that your brass is a bit too long. I have had two guns with this issue and need to shorten my brass to use it in these rifles.

Here is what I would try. Take a piece of unprimed brass, slide it into the chamber and see if the bolt will close completely without a lot of force. Then will it eject. If it does then skip down, if it gives you trouble your problem is probably the overall lenghth of the brass. Nobody makes a cheap .300 whisper case trimmer but if you buy a lee trimmer for a 7.62X39 (bet the spud, shell holder and cutter) you can shorten the pin and get the length you need. Slowly shorten the pin till you get the current length then shorten the pin a little at a time and recut the brass till it chambers. If you want to see if shortening the brass will solve the problem before buying a case trimmer you can shorten the brass using a piece of sandpaper on a flat surface but do not try to use this cartridge for loading as the case mouth will probably not be square.

Now if your brass goes in without any problems and doesn't need to be trimmed then the next thing I would do is to work with your bullet seating depth. Again use a sized case without a primer. Seat the bullet to your normal depth. This give you a starting point. Now try to chamber it using very little if any force on the bolt. Take a measurement on the bolt to give yourself a reference point. Now turn your bullet seating die down 1 turn. Try the round again, does the bolt go further? If so you are going to have to play with your seating depth. Each manufacturer has a different profille to their bullets and where the bullet starts to go to maximum diameter can be in a different location depending on the bullet mfg. and style. In other words you may find that seating a Sierra Matchking 168 Grain bullet may require a different seating depth to get it to chamber than when you use a 168 grain Speer bullet. This can have to do with the throating in the barrel when the chamber was cut. If you have a short chamber you will need to seat the bullet deeper in the case or use a smaller profiled bullet.

If this isn't he issue then you might want to make up some brass out of .221 fireball brass. The necks on this brass (since you are expanding it from .221 to .30) are thinner so if the chamber is tight and the neck thickness is giving you trouble this should correct that.

Hope this helps, I have had a number of .300/.221 (whispers) in the last year or so and found they all have certian quirks. This is the nature of wildcats and also what draws many people to them. Be warned once you wander into the world of wildcats you either run away screaming or start looking for more. There is NO MIDDLE GROUND>>>>>>>>> I am looking at a .22 spitfire built on a M1 Carbine frame to add to my list of calibers you cannot walk in and buy ammo for

Drop me a note if you have any questions......

DonT

[Gelandangan]

Hi DonT

The first thing I check is the case length and OAL Thats even before I load the first live load. I am sure that my case length is correct as measured against the lead cast of the chamber (1.350"). Also, I am sure that the OAL is correct (2.245"). Also the head space is correct.

The only variable I am sure of is the case neck thickness. I may have to ream my cases to reduce the neck.

I worry that I may encounter this problem in the field in middle of a hunt. It may get dangerous. I am reluctant to chamber live ammo in the gun at home to try them one by one. But this I may end up having to do. Maybe in the back yard behind the laundry.

Gelandangan

PS. thanks for the tip about wildcats. this will be my second one. The first one around, I have to get a reamer and reloading dies made up just for it. At least for this one, I could buy them off the shelves.

[DonT]

Again if you haven't try what I suggested. Only takes a few minutes and may elimate you having to turn necks.

Also as I suggested try .221 fireball brass before going to the work of of neck turning. The reason I suggest his is when you use .223 brass you are necking the brass down. This has a tendency of "thickening" the neck during this process. When you use .221 brass you are "stretching" the brass as you neck it up.

DonT

[Lawfficer]

Click the link to my site below, read through and see if that helps at all.

[Gelandangan]

@ DonT:
I did what you suggested and found that there is indeed no error in the case sizes. I found out that my Redding die is a tad large, and the PTG chamber reamer is a tad small. So I get a very very tight neck chamber. A few of my loads could now get into the chamber after a very slight (just a hair) crimp at the end. Thight neck would normally gives better accuracy, but it may be a problem in the field when I need the gun in a hurry.
I may have to get the chamber freed up a bit.

@Lawfficer.
There are some more data I want to know but is not in your site :P and they are:
1. Dimension differences between different reamer makers (PTG, Clymer, JDJ etc) in 300/221
2. Dimension differences between different DIE makers (Reddings, RCBS etc) in 300/221

These infos would reduce problems like what I had.

I seems to recall that there is a site that gives out chamber reamers dimensions cut by different makers but I could not find it now...

Gelan

[DonT]

Gelan,

I am going to have to look to see what I have for dies. Green box but not sure if they are redding or Rcbs. If they are different than yours I would be happy to send you a few empties sized in my dies to see if they work.

Also I am serious about trying .221 fireball brass you will end up with thinner necks and this may solve your problem with no need to open up the chamber dimension, a much simpler fix than recutting the chamber!

Although not an expert it is my understanding that when the cartridge was originally developed the parent case was the .221 fireball not the .223 (5.56 nato) case. I might have a few of those around I can send you also...

DonT