40XB: Work in Process

[shooterman_zero17]

Updated:
Just picked up this rebarreled 40XB yesterday.

It:
-Is US marked (not USMC or US PROPERTY)
-Has the original stock
-Has a Benchmark Barrels .17HMR 24" barrel installed (unsure of contour, didn't measure when I had it out of the stock)

The action is in fairly good shape; light wear is evident on the side of the action where the rear sight lived. One small ding on the left side unfortunately.

Not sure who smithed the barrel onto the action, and am trying to find out still.

 

[Jrb572]

700 SA rails and trigger will work on them. I would keep the original trigger and have someone adjust it back to the weight you want.

 

[DanGroves]

Jrb is correct on the rails and trigger. I agree you should keep the original trigger...

Quick way to tell the difference between a 40X and a 40XB is the bolt handle. 40X had a straight bolt with a round knob. 40XB has a swept back bolt handle with a 700 style knob.

First thing to check is if the SN etched on the bolt matches the SN on the receiver. And, if you intend to run it as a 17HMR, it should be GTG. If you want to rebarrel it to .22 RF, the bolt face will be over-size for the HMR head. I converted a 40X .22 RF to .17HMR and had to open up the bolt face and move back the bolt stop and ejector to extract a live round. Extractors worked flawlessly for the 17 HMR.

 

[shooterman_zero17]

700 SA rails and trigger will work on them. I would keep the original trigger and have someone adjust it back to the weight you want.

Quick way to tell the difference between a 40X and a 40XB is the bolt handle. 40X had a straight bolt with a round knob. 40XB has a swept back bolt handle with a 700 style knob.

First thing to check is if the SN etched on the bolt matches the SN on the receiver. And, if you intend to run it as a 17HMR, it should be GTG. If you want to rebarrel it to .22 RF, the bolt face will be over-size for the HMR head. I converted a 40X .22 RF to .17HMR and had to open up the bolt face and move back the bolt stop and ejector to extract a live round. Extractors worked flawlessly for the 17 HMR.

Will definitely keep the original trigger.

This is a 40XB then; it has that 700 style bolt handle. That's actually part of how I IDd it initially.

I would assume that the considerations for .17 HMR were made for the bolt face/extraction when it was rebarreled. It has definitely been shot since rebarrel...I'm hoping to run some of that info down today.

Pictures and more to follow.

 

[shooterman_zero17]

Original Post updated with a couple of pictures.

-Range report next weekend
-Will have glass, rings and base ordered and hopefully delivered this week

 

[Hushkaboom]

If the serial number ends with B then it is a 700SA based 40X B.

 

[DrDeath]

Let me know when you want to sell it!!!!!

 

[shooterman_zero17]

Was on the hunt for an SWFA mil 16x, but none were to be had, so this has taken a couple extra weeks to get online. Did luck out and managed to find 500 additional rounds at about .40 cents per round last week (which is about the going rate for .17HMR locally).

I was on the fence about getting big glass for this rifle. While scouring the PX, someone had posted that Midway was running fair discounts on some Bushnell offerings.

Hopefully by the end of the week I should have:
-EGW 0 MOA base
-ARC M10 34mm Lows
-Bushnell XRS II 4.5-30x50 with an H59

Assuming everything gets here on time, range report this weekend.

 

[orkan]

-Has a Benchmark Barrels .17HMR 24"

I wasn't aware benchmark made .17cal barrels.

 

[shooterman_zero17]

I wasn't aware benchmark made .17cal barrels.

I checked their website before I picked the gun up and noticed the same.

I never heard back from the original owner (who put it on consignment) to find out who plumbed it all together.

ETA: maybe it was an offering made previously and discontinued or special request/order?? I'm not as familiar with their brand so I can't speak to it otherwise. Unfortunately have no clue as to the age of the barrel or when the rebarrel was done.

 

[shooterman_zero17]

Finally got to the range yesterday.

Shot from sitting, 100 yards, 1" dots. 5 rounds per group, using each type of .17HMR I've got on hand. Using a Wiebad bag up front for support. Haven't actually measured them yet.

The wind wasn't quite a factor here as it was on some other groups I shot with this rifle beforehand, or with the groups out of the 452 shown below.

What's interesting is how the groups slowly climb over the course of shooting them...the POA was dead center of the dots each time. This was also shown on a 15 round string (3, 5 round groups) of the 20gr FMJ I shot (and ended up rather windblown).

So, I'd say confidently that the climbing nature isn't based on ammo type to type...it was consistently doing so.

Also took my CZ 452V (bedded in a Manners T4) and re-zeroed it. Shot some groups in the same manner as a sort of "control" to show same shooter, gun to gun (same conditions). But, shot with an Atlas on the rifle for stability.

(ETA: these groups in the first image do reflect a little more wind...the second image was a little earlier when it wasn't nearly as strong. POA was on the corner of that orange square. Those are 1" squares.)

I've got some Norma 17gr VMAX inbound this week. I was unaware they even had a 17HMR offering, so I'll be making an effort to shoot some of that next weekend.

Initial thoughts on the XRS II...
-Good glass...stiff magnification ring...
-Didn't shoot everything on 30x mag...played around with shooting those groups between 15x and 30x...
-Glad I went with the H59 instead of Tremor 3 (rather have mil holds than wind dots for this application)...reticle thickness lent to being useable here, even up to 30x...
-Definitely easy to spot hits without using a spotting scope at 30x...I'm used to shooting my 452 on fixed 16x mag and definitely use a spotter to dissect a group when needed...