My M305 Project (range update in last post interesting results)

[sobo4303]

My $.02 also.

I noted in a thread someplace that you chrono'd your reloads and they were over 2,800 fps. Back in the day, I read one source which stated that the rifles were designed for 2,700 and another for the 2,750 mark. I load mine to the 2,700 mark. I also use the Win 748 ball powder with a mag primer.

I also noted and the Doc also commented that the bolt may not be closing to the point using a test with live ammo. I discovered that unless you use an empty case, physics will dictate that a live round (with it's additional weight of the powder and bullet) will not behave the same as an empty case.

I know you are neck sizing, but, just out of curiosity, are you trimming the cases as well to ensure their overall length are within spec?

I had a scope mounted on mine and found that the mount interfered with casing, really dented the hell out of them, no stovepipes though. I removed and narrowed front sight. Because I am getting into the BPCR shooting, thought it best to get used to sights. I benchrested rifle and meticulously shot at the target to see where rifle was shooting. I was amazed and now shoot the gongs at 300 yards on a consistent basis. My brass thanks me!

 

[mountainspruce]

"I did have 8 stoppages but they were all caused by the ejected case getting caught between the oprod and my Arms mount right at the base of my front set of rings."

"I had a scope mounted on mine and found that the mount interfered with casing, really dented the hell out of them, no stovepipes though. "



The ARMS18 is not a perfect "out of the box" scope mount and the stoppages you speak of are well-known. On some rifles you need the skills of an expert like m14doctor to make it work. It's a "crap shoot" sometimes with that one.

 

[TACTICAL111]

Stat reloading at this point no major accuracy gains yet I blame my rounds

Good start point:

Win/Rem cases, Sierra 168 HPBT, IMR 8208 @ 41 with CCI's.

My current load is very similar:

Lapua brass
Lapua 167 HPBT Scenar's
CCI
IMR 8208 @ 41.0

Gas system: 2009 Poly cylinder (non-unitized) & lock, Sadlak TiN piston, Sadlak guide rod/buffer & USGI spring.

"I did have 8 stoppages but they were all caused by the ejected case getting caught between the oprod and my Arms mount right at the base of my front set of rings."

The issue is your stock bolt springs. The ARMS 18 on a Poly may eject cases between the op rod and receiver.

Solution is to swap out the ejector spring/plunger & extractor spring/plunger with USGI. This will change the ejection profile of your rifle from forwards to sideways.

The ARMS 18 mount is very low & the best mount out there IMO, just requires the bolt springs on some Poly's to be changed to USGI which alters the ejection profile.

NO more jams & secure optics.....Life becomes very good.

 

[mountainspruce]

The issue is your stock bolt springs. The ARMS 18 on a Poly may eject cases between the op rod and receiver. Solution is to swap out the ejector spring/plunger & extractor spring/plunger with USGI. This will change the ejection profile of your rifle from forwards to sideways.

There's one fix for a common problem with Norinco/Polytech, or, maybe not so common? Thank-you. I would have kept mine if I did not have to remove material from the mount to install it. One too many "issues" it seems... .

Why don't you try shooting your rifle with irons? Let's see how many problem creep up...

 

[Freerider]

Wow I am surprised to see this thread pop again after so long and just when I was thinking of updating it. To answer the question about the redfield 2-7 I had the accumark reticle and loved it. That being said I just sold that scope to another member on here. I decided to upgrade to the Vortex Viper PST 2.5-10X44 with the EBR Mrad reticle. I wanted a scope that I could dial for range and elevation. I have had that scope out once so far and what a world of difference but one would hope so for the $500 price difference from the Redfield.

I did no shooting this summer and have only just recently got back out with this rifle. I have it in the USGI fibreglass stock that I mentioned before. I also decided to start over on my reloads as I think a lot of my problems were coming from my brass. Been out a couple times the last month mostly just to fire form my new brass and some initial load work up and have been seeing some very promising results. I am still having problems with brass getting caught under my ARMS mount and I am planning on ordering a new set of springs. I have noticed that I usually fire the first 30 rounds or so with no stoppages and then I'll get progressively more as a fire more ammo. I am hopping to get out in the next couple of days and take a bunch of pictures and update.