Diana mod 45

Diana Model-45 DRP.

According to John Walter the model 45 DRP [ie the 2nd model prewar model 45] was the first Diana gun to feature the independent-cocking double pull trigger and was introduced in mid-1931.

Diana Model-45 DRP - Auctioned.

This good condition DRP Diana 45 sold at auction for 467 euros.

Diana Model-45 DRP - Transitional.

With thanks to Mike for permission to use the following pics (x6). It is clearly a 1st pattern, with single pull trigger, solid trigger block and no model number stamped on the cylinder. But it also has a keeper screw fixing the loading tap retaining screws and another securing the cocking link pivot bolt, both features common to the later DRP model 45s. It also has the later 'modestly dressed' goddess.

With thanks also to the rifle's new owner, Mike D, who provided the subsequent 18 detailed pics lower down this post.

Mike D's pics start here:

Diana Model-45 DRP - First Series 06/1931.

This is an early pattern mod 45 with a "6 31" date stamp below the breech. It has a non-original cocking lever catch which is slightly too long, meaning the lever won't lie parallel to the barrel. The front sight has been adapted to accommodate a new white plastic bead which is useful when sighting on a dark target.

Much of the original blueing is intact, although the finish is quite worn on the trigger block and there are a few small areas of pitted metal. Overall it's a lovely, largely original rifle that shoots powerfully and accurately.

Diana Model-45 DRP.

Thanks to a collector friend for letting me take these pics.

Diana Model-45 DRP - First Series 04/1930.

With thanks to RB for these pics:

Diana Model-45 DRP - Late 1930s.

With thanks to Petra for these pics:

Diana Model-45 DRP .

With thanks to Tomáš for these pics:

Diana 45 DRP serial no. 125 

With thanks to Matthias. 

He says this "Here's a little text on my experience adjusting the pre war Diana two stage trigger:

The trigger is adjusted by a single screw that is secured in place by a locking screw from the front.
Turning the screw out will lengthen the pull of the first stage while reducing the weight of the second. If it is too far out, the second stage becomes indistinguishable from the first and the rifle fires unexpectedly.
Turning the screw in shortens the travel of the first stage and while making the second stage more noticeable it also increases creeping.
With the screw too far in, the first stage vanishes. What's more, the second stage will creep quite a bit and again, the gun will fire unpredictably.
The challenge of adjusting this trigger is to find the balance between those two extremes. I've found that there is really just one optimal position so the trigger can't really be described as customizable. It causes a fair amount of rumbling being cocked but if adjusted just right, breaks just as crisply as Diana's post war ball bearing trigger."

Diana mod 45 DRP restoration 

With thanks to Steven for these pics.

He said: "rebuilt the seal was a smidge tight n the cylinder and the velocity was just under 400FPS average with the RWS Meisterkugeln 14gr. pellets. The rifle now has over 200 pellets through it since restoration and velocity is up to 442FPS average from a 20 shot group with an ES of eleven. That is around 6.1 FPE."

These pics he took before the restoration.

"Metal and bluing is in great shape for its age. A few minor specks of rust which easily faded using OOOO wool and oil. The stock had some bare areas where the finish had worn off plus a bit of flecking around the edges of those spots. Wiped it down with mineral spirits to remove any old wax and grime then blended those bare areas using Tru-oil to protect it from further damage. 

"Leather piston washer and seal had decayed beyond proper function. Possibly caused by the lead chunks found in chamber. Hard to say how they ended up there. I don't think the transfer port is large enough for a .177 cal. to fall through."

"Cut and formed new leather seal."

"Alert For any person disassembling one of these please note the lug that the stock bolt screws into is left hand threaded. Stock bolt itself is right hand threads."

"A bit of background on this rifle. When I received it the piston stem would not lock into place. I assumed it had worn parts, maladjusted trigger or possibly some grit preventing the sear from engaging. After disassembly and thorough clean, I inspected for worn parts and found nothing notable. Still the piston stem does not latch, although the trigger does reset during cocking operation and releases when pulled.

"I had actually tested it before reassembly by pushing the piston into the assembled trigger block while holding down on that spring with my thumb and it seemed to lock in place and release with trigger pull.

"Perhaps the piston slot has worn a bit. If the tolerances are tight it may cause it to come up a bit short. "

"Tested by inserting a cut piece of 1/4" brass dowel between the foot of the cocking lever and the end of the slot in the piston.

" Eureka!! It cocked and fired. Could be wrong but it looks like minimal wear on the cocking foot, so I think all the wear is at the lower end of the slot in the piston.

"Finding a replacement piston is probably out of the question so building up that area with a TIG welder would be more practical. Hard to tell how much metal should be added without another one to compare to. I believe 1/4" would be too much and cause impact with foot when fired. Below is a measurement taken at the lowest point in the slot."

"The slot wear does not match the rest of the rifle. I did notice the screw heads are a bit buggered which leads me to believe the rifle has been apart in the past. Closer inspection of the piston slot in that area reveals what looks to be some unusual file/sanding marks. So maybe it isn't wear at all. It makes sense that when the leather piston seal crumbled, it would allow the rear of the slot to slam into the cocking foot when fired resulting in mushrooming or elongation. At that point a repair may have been attempted by filing the mushroomed area. This is all speculation of course. The walls of the tube look great but the end of the chamber at the transfer port has taken a beating.(dry firing?).

"The measurement from the lowest point of the piston slot to the edge of the skirt was .281 inch.

"The rifle cocked and fired normally. The piece of delrin measured .207 inch.

"A total measurement of around .500 inch would work and also still have plenty clearance between cocking foot and end of piston slot when fired.

"Photo below shows rough measurement after using a TIG welder to build up the slot. Removed excess metal on lathe and reformed the slot with a dremel tool."

Interesting side note.....

Upon re-assembly I discovered that those two small set screws on each side of the trigger block aid 
in adjusting the trigger housing. If the screws are too far in, it will prevent the notch in the 
piston rod from engaging the locking sear. If they are too far out the very tip of the piston rod 
does not clear the locking nose in the trigger mechanism and prevents full cycling of the cocking 
arm. Those screws look to have been staked at some point also.
When correctly adjusted, all the parts cycle perfectly and the feeling can only be described as both 
smooth and clunky at the same time."

"The trigger is actually quite nice. First stage travel is a bit long but has a very smooth feel and breaks clean at the second stage with just a micro amount of creep. It can be adjusted for a single stage feel by turning the adjustment screw in."

Diana mod 45 (1st pattern, double set triggers) 

With thanks to Steve for the heads up.

See also:

https://forum.vintageairgunsgallery.com/pre-war-diana-air-rifles/diana-model-45/#post-2301

for a rifle stamped on the barrel and stock by the same German retailer.

Diana mod 45 compared to Webley Mk3 

With thanks to Mike for these pics.

Diana mod 45 (aftermarket beech stock?)