.338 Win Mag. problem

[FGT]

I have a Remington mdl 700 bdl in .338 win mag that is giving me serious extraction problems. Yesterday I tried 5 different loads with new brass using IMR 4350 behind a Nosler 180 grain bullet ranging from 72 grains (very mild) to 74.5 grains all well under the maximum loads specified in several different manuals. Velocity varied from 2900 fps to 3090 fps amd was fairly linear in proportion to powder charge. At any velocity above 3000 fps the bolt would open easily enough but I could not get it to move rearward with out considerable effort.
I have had similar problems with H 414 and VV 140 with appropriate mid range loads. The velocities are well below the specified maximums. I checked the distance from the bullet to the lands and it was from .010 to .011 all within specs. The velocity is low but correct for my powder charges and barrel length but the rifle is acting like I have excessive pressures. Some of the brass that has been fired with the heavier loads exhibits a tendancy to grow in OAL by as much as .085 ". Does anyone have an idea of what the problem may be? This rifle has less than 100 rounds through it.

 

[critter]

What brand of brass? Some brands (Rem--??) are said to be soft which MIGHT be a problem like yours. I'd try a different brand of brass to see if it made a difference. Fed brass is good brass in handgun calibers.

 

[Geno]

Check your brass length

When I had a Rem 700 Classic, chambered in .338 Win mag, I used to put through some extremely hot loads with Speer Hot Core 200 Gr. Spire Points (3,171 FPS) with AA 3100 and a Fed 215 primer. That sort of velocity had a tendency to quickly lengthen the brass and it would begin to rub against the front of the chambering. I used to have to trim it rather frequently. Note that different powders' burn rates can effect the brass lengthening too. The faster it burns, the faster chamber preassure rises. What powder are you using?

Wow, how did I miss the powder listed???

That does burn faster than the AA3100. You might want to check the brass length frequently. For brass, I like Federal.

Doc2005

 

[Grumulkin]

If you're getting high pressure signs, believe them and back off.

Make sure the chamber isn't dirty. If the cases are too long (i.e., not trimmed adequately) this can cause high pressure at "normal" powder charges. If your bullets are seated so they are hitting the lands, this can also cause high pressure.

How does a unfired sized case chamber and extract? If an unfired case extracts with difficulty it means there has been case expension near the head where the normal die won't resize a belted case. A special die (the name of which slips my mind at the moment even though I have one) is needed to resize a case in this area.

 

[temmi]

100 years ago when I was young I had a Brand New Rem 700 BDL in 338WM. I had the same problem with Factory Loads. Turns out the chamber needed to be polished… Sent it back to Rem and they did it.

Never had any more problems

 

[GooseGestapo]

Are you full length sizing?

If so, what make dies are you using?

If you are full length sizing, and you have a chamber that is on the long side,
AND, IF YOU ARE USING LYMAN, OR POSSIBLY SOME OLDER RCBS, OR PACIFIC DIES;

you are inducing a condition of excessive head space.
This is because that with most of these dies, if you screw the die down until it contacts the shell holder, then you are setting back the shoulder everytime you size the case, and with especially the Lyman dies, you are inducing excessive headspace.

The thing that makes me suspicious of excessive headspace is that you state that your cases are growing excessively.
With the relatively straight sidewalls of the .338winmag case, and 25deg shoulder, case growth shouldn't be an issue if the headspace of the loaded ammo is correct, particularily if you are setting the sizer die to just "kiss" the shoulder of the case on resizing.

If such is not the case, I suggest you take the rifle to a gunsmith that can examine the chamber and check it with headspace gauges to verify everything is "ok".

Another thing, you didn't tell us what brass you are using.

I obtained a new Rem m7 in 7mm-08 in '04. With factory loaded PMC ammo, I was having similar "symptoms" that you are describing. Reloaded brass would chamber only with difficulty, and velocities as well as pressure signs were indicating excessive pressure.

I tried some "reformed" .243 brass from Winchester brass. None of these symptoms were exibited. I tried inserting a bullet into the fired PMC brass.

THEY WOULD NOT FIT !!

After miking the case necks, it was obvious that the necks on the brass was excessively thick, and the throat of the rifle was on the "tight" side of normal, normally a desireable condition.

After obtaining a .284 pilot and neck-turning the brass, it is THE most accurate brass in this rifle.

Check some of these things out and report back.

I'm interested in what turns out.