GP100 44 Spl 5 Inch Half Lug

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BABore

Bearcat
Joined
Dec 23, 2011
Messages
7
I picked up a Lipsey's 1770 a few weeks ago and began load development. Being a bullet caster, I measured all of the critical features and checked for any barrel constrictions. It was all good with uniform 0.4312 cylinder throats and a 0.004" cylinder gap. I worked up loads with Unique and Power Pistol in 1/2 grain increments using my 429421 HP bullet at 240 grains. I kept all of these loads at or below the SAAMI 15.5 kpsi limit for the time being. All was good until I saw that the first shot at 25 yards was about 10" high.

When I went to turn down the rear sight, I found that it was only 3 clicks from bottoming out. Bottomed out it was still hitting 6 inches high. I went through my 80 rounds of test loads and found a few good accuracy points. I checked the barrel during several breaks for any leading and found a nice shiny bore. That evening I looked through the Brownells catalog, Novak web site, and several others without much luck. Last Monday I came here and dug back about 4-5 pages back and saw that there were others with the same issue. I also saw that there was very limited resolution from Ruger or other sights. So, I began the process and called Novak first as it is their 0.265 high front sight. They said that it indeed was theirs, but the rear sight was Ruger's so I should call them. I did look on Novak's web site again and they do offer a 0.300 front. I knew it wasn't high enough, so I didn't bother. A call to Ruger was a waste of time. The rear sight is common to several of their different platforms, but they don't offer a shorter rear blade. When I explained all of the above, they wanted me to send the gun back for evaluation stating that it could be the crown was bad. Even after I told them that I had shot several 5 shot groups around 1 inch. I declined and moved on.

Last Tuesday I returned to a website that I had found a sight height calculator on, Dawson Precision out of Texas. I re-ran the numbers and gave the distance I was shooting high as 12 inches. I was only 6" high, but the rear was bottomed out already. The calculator said I needed a front sight 0.352" high. Dawson does offer sights for the GP100, but they aren't any higher than mine. After poking around there a bit, I saw that they do offer front sights for Novak dovetail cuts. While they appeared to be more for 1911's they looked liked they may work. They did not list the dovetail height which was important as there is a 0.060" and 0.075" dovetail versions. They off a standard black serrated ramp, fiber optic, and night sights in a big list of increments well over what I required. I wrote down the part #'s for a 0.340 tall fiber optic and a 0.330 black and gave them a call.

I explained the whole situation and they ran the numbers again, matching what I had. Their Novak cut sights offered are all 0.075" version which I found out was the standard Novak cut, 0.330" wide x 0.075" deep, 65 degrees. Dawson agreed on my sight choices and suggested that I order them on-line as I would get free shipping. I received the two sights on Saturday and got the black ramp (SKU #050-935-00) installed right away. The factory sight did come out hard. The sight needs to be removed from to the left to the right if your looking from the rear or normal shooting position. As I was planning some more test loads for yesterday, I put all of the tools in my range box along with the fiber optic sight (SKU #050-532-00).

My sight height choice worked out near perfect. I tried both 200 and 240 grain loads and I had plenty of adjustment range. Hope this all helps out the next Ruger sight victim.
 

BKDinTexas

Bearcat
Joined
Apr 22, 2010
Messages
66
Thanks for the good info. I was about to order one of these but I think I will pass. The 44 Specials seem to really vary on elevation with different bullet weights. With my 3 inch stainless GP100 44 Spl sighted in at 25 yard with 240 cast semiwadcutters (7.5 grs Unique), the Speer 200 gr. Gold Dot factory loads hit about 5 inches low. I have enough adjustment to bring them to center, but what a pain. My 3 inch is a dedicated heavy cast bullet gun now. Even with the 240 grainers I got lucky as the rear sight is completely bottomed out to get them centered at 25 yards.
 

CraigC

Hawkeye
Joined
May 27, 2002
Messages
5,197
Location
West Tennessee
Thanks for the info, I got a nice package from Dawson while I was out of town. Interested to get the installed and do some shooting.
 

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