Daggaron,

I've got a 700 LSS .375 Ultra and I love it, but I'm looking at building another to compliment it. I'm looking at going the CZ route, and noticed in other posts that you have done one.

I was wondering how well yours fed and it you had any problems obtaining proper feed?

Thanks in advance for any feedback.

Badboyz,
The CZ 550 Magnum in 375 H&H makes a simple rechamber job to convert to 375 RUM, much like doing a 458 Lott on the 458 WinMag.

It will feed straight off, but kind of rough.
I didn't ask the gunsmith to do any feed work as I thought it would be O.K., so I ended up doing the following:

Grind/file/sand/polish smooth the feed rail undersides and lateral edges without changing their contours much, except to smooth them. I used some gunsmith files, fine abrasive paper, and a Dremel Tool with grinding and polishing tips.

Do the same to the feed ramp. Here I used the fine grit paper over my index finger tip, applied elbow grease, then the Dremel Tool polishing spuds.

Then I cold blued all the surfaces I had polished, and then lubricated with Break-Free CLP.

The 375 H&H extractor and ejector work fine. I polished/deburred the contact edges of the extractor with the Dremel spuds too.

Initially, if the cartridges were all the way to the rear in the box, they would sometimes misalign and sit a little low and be over-ridden by the bolt, because the rim of the 375 RUM is rebated by 1/100" radius.

I did some extra grinding on the rear underside of the feed rails, to thin them just a tad like 1/100" and blended it forward.

I also installed a stronger magazine spring that came from an FN Mauser. The one that came with my CZ action seemed to be a little weak.

Now I have a positive and slick feeding 375 RUM.

There is about a quarter inch of extra magazine length in the CZ 550 Magnum.

A spacer at the rear of the box would keep the cartridges forward in the magazine, sitting right at the edge of feed ramp. A potential refinement to be made.

The current CZ follower is not full length in the box. This could be another refinement to be made, a longer follower, possibly thinned and opened up a bit in its contour near the feed ramp, for the broader shoulder of the 375 RUM. The current one works fine, with the above refinements.

The box holds four 375 RUM cartridges, and allows a fifth to CRF off the top of the box, so the loaded gun capacity is five rounds.

Here is my parts gun:


[ 02-01-2003, 22:47: Message edited by: DaggaRon ]