Over the years, I cannot tell you how many times my friends and I have talked about building the perfect bolt gun. We would discuss which features to include from different receivers and so forth until we created the perfect action! While scrolling through my Facebook newsfeed, I came across Ultimatum Precision U300 and it caught my attention. Many of those key features we had talked about have been included in the U300, in particular are the integral recoil lug, 60 degree bolt lift and side bolt release. The receiver also uses a Remington 700 footprint, meaning it will work with the chassis and stocks I already own! But more on that later…
The U300 is a 3 lug receiver manufactured in Canada. The 3 lug design allows for a short 60 degree bolt lift, compared to 90 degrees with a 2 lug receiver or 70 degrees if we’re talking about a Tikka. Ultimatum also uses Remington 700 triggers and incorporates the ability to switch out floating bolt heads. They offer .223, .308 and magnum bolt faces. This allows you to shoot different cartridges simply by changing the bolt head to the appropriate bolt face, barrel and possibly the magazine depending on the round. You can finally stop moving your scope from rifle to rifle! One of the first thoughts that came to mind was utilizing the .223 bolt head so that I can also run my comp rifle as an inexpensive trainer. Later, when needed, I could install the .308 bolt head and torque in my 6.5mm Creedmoor barrel for competition use. This can easily be done with a barrel vice and action wrench. The U300 can also be used in conjunction with a barrel nut, further increasing its flexibility for the end user. Ultimatum Precision included additional improvements like a stronger rear tang and minimum ejection port. This in addition to the receiver’s lack of raceways increases rigidity. The receiver is made from 4340 nitride treated steel. Also incorporated into the U300 is a battery safety ensuring the rifle will not fire if the bolt head is not properly installed.
When the Ultimatum U300 action arrived at DMR LLC, everything ascetically looked great. The receiver, assembled bolt, trigger hanger, 20 MOA scope base and trigger pins arrived in handsome packaging with a high density foam insert cut out for the main components. Ultimatum included an instruction manual and detailed drawing for machining the barrel.
As I inserted the bolt into the receiver and began to lift the handle, I noticed heavy resistance. I’m not sure exactly how heavy it was but it was a disappointment. I heard that a modification was in the works to address this issue but don’t know exactly what it would consist of. I assume it’s going to be a reduced tension firing pin spring. Although initially, I was disappointed, the fact they were already working to fix the issue comforted me.
I had the opportunity to touch base with Mr. Brisson from Ultimatum Precision and he informed me the updated kit consists of a new bolt body, firing pin (0.068” diameter), bolt shroud, sear, firing pin spring and bolt head. So basically ending up with a new bolt, only reusing the bolt handle. The update will also include a second firing pin spring which is meant for use with hard primers like those found with surplus ammunition. When utilizing the stiffer spring, the bolt lift resistance will increase but will still be lighter and smoother than when my action first arrived. This spring will also provide a faster lock time so those who don’t mind the added resistance will benefit. Customers ordering an action will receive theirs with the update installed, which will be standard from this point on. Actions that were already delivered will be receiving the update kit sometime after Shot Show 2017. Ultimatum Precision has a 100% satisfaction guarantee so if you’re unhappy with the action or the update kit doesn’t quite do it for you, return the action and get a full refund! After getting off the phone with Mr. Brisson, I felt assured the problem would be fixed.
So what happened? I was told the initial bolt had tolerances that were too tight. The firing pin spring tension and mating surfaces between the bolt assembly and receiver produced a lot of bolt lift resistance.
So what’s up with 3 lugs? Many shooters really like the short 60 degree bolt lift provided by a 3 lug. Many who walk away from their first experience with an Accuracy International or Sako rifle will remember that short lift. Traditionally a shorter bolt lift will have more resistance because you are overcoming the same spring tension in less rotational distance. I’m not sure what AI or Sako have done but they certainly seem have it figured out. Other aftermarket 3 lug receivers haven’t been able to find that same sweet spot. Some manufacturers use a tension adjustment to achieve a light lift but are running at the ragged edge of reliably setting off primers.
I decided to go ahead and build my rifle in lieu of the bolt update kit (I do not recommend doing that). I used a Bartlein stainless steel blank and will chamber it in 6.5mm Creedmoor. My receiver has a 1.0625” x 16 tpi tenon – current versions of the U300 use a 1.0625” x 20 tpi tenon making it compatible with small/standard shank Savage pre-fit barrels and will feature a redesigned rear tang that is different from the one on my action. I chose the XLR Industries Carbon Chassis in a Rem 700 short action footprint for this rifle. This is where I ran into issues and kicked myself for not sending the receiver to Nick at XLR so he could make sure it would fit correctly. I was actually surprised when he offered and it stands as a testament to the customer service they provide! The rear tang was too wide and kept the back of the receiver from properly seating. I also needed to open up the recoil lug recess another 0.010” because the fit was very tight. Thankfully I was able to get the chassis to DMR LLC and have slight modifications made to correct the issues. I would have rather avoided doing that but with time constraints I decided to make it work. I believe the recent revisions of the rear tang will help others avoid this issue but I can not say with 100% certainty. Once we finished and reassembled the chassis we did a test fit. When I went to insert a magazine it wouldn’t engage the latch. So to fix this, we ended up disassembling the trigger guard, removing the magazine latch and milling 0.030” off the top of the latch. Doing this allows the magazine to properly engage and feed. I also noticed I had to remove 3 threads from the rear action screw to keep it from protruding above the receiver. The final task to mating my U300 receiver to the XLR Carbon chassis was to remove the mirage hook from the 20 MOA base. This was done quickly once tooled up in the mill and now allowed the carbon fiber handguard to attach. These issues are a case of a Remington 700 footprint verse Remington 700 compatible. That may turn some people away because of the inconvenience it causes and because not everyone has access to the tools or has the know how to fix it. I am in debt to DMR LLC and Michael Nitzschke for working their magic in such a timely manner.
Ultimatum Precision’s bolt update kit arrived a few weeks after the U300 receiver and things were very busy because of SHOT Show 2017. We have been waiting as patiently as possible for this update kit and now the moment of truth was near. I felt nervous about the bolt lift and tolerances. I had my fingers crossed that I wouldn’t need to pull the barrel to re-headspace it and that the bolt update kit fixes the heavy bolt lift issue. After my trials and tribulations with this build, I was ready for everything to finally come together… and it did, kind of. They were not able to get the replacements to us in time for our testing. They were however, able to provide us with a “prototype” bolt with the update installed so that we could use it and experience the new bolt lift for ourselves. The actual replacement bolts could arrive shortly after SHOT Show but I wasn’t given a timeframe. With the bolt provided by Mr. Brisson installed, the lift feels great and really makes everything come full circle for this receiver! We estimate they reduced the bolt lift by about 35-40%. I went ahead at tested headspace with our go/no go gauges and it passed with flying colors. All that was left to do now was to have Jason with DMR LLC prep and Cerakote the barreled action so we could do our final assembly!
Ultimatum Precision is continually improving their products and expect future changes. Marco Brisson has been extremely responsive and professional. I believe in time they will have compatibility issues sorted out so we can better focus on the many positive attributes of the U300. The issues I faced may deter some, and that is understandable, but if you are interested in utilizing this receiver for your build remember to take the extra time and make sure your components will fit together correctly. This will ensure the process will go smoothly.
Ultimatum Precision actions are available in short action, long action and .338 Lapua magnum length receivers. You can have it configured for right or left hand shooters and select which side you prefer the ejection port! Despite the issues that needed to be overcome during this build, I admit I am very happy with the completed rifle. The list of things I like, is longer than the list of things I don’t and the rifle is shooting exceptionally well. I suggest keeping an eye out for future offerings from Ultimatum Precision. I have heard rumors of some really cool things they are working on and hope I have the opportunity to share them with you! I will update everyone soon on how the U300 action is performing after I get more rounds through the rifle.
What I like:
• Intergral recoil lug
• 4340 Steel Construction with Hard Nitride treatment
• Removable floating bolt heads
• 60 degree bolt lift
• Remington 700 trigger interface
• Bolt stop/release- The bolt stop uses a threaded fastener versus a pin/roll pin and access to the fastener is recessed under the scope base. The bolt stop also functions as guide for the bolt body since the receiver doesn’t use raceways.
• 20 MOA base- The base attaches to the receiver with 6, 8-40 fasteners and utilizes two large pins to ensure the base doesn’t move. I also appreciate the the base is made from steel.
• Barrel nut- The barrel nut offers a lot of flexibility for shooters and allows them to self service the rifle when it’s time for a new barrel, or if they want to change cartridges.
• Battery safety- I like that it won’t fire if I for some reason incorrectly installed the bolt head.
What I’d like to see change:
• Footprint- The Remington 700 footprint is not what I’d like to see change but rather, I would like to see the compatibility improve. I had issues fitting the receiver to a chassis designed for the Rem 700 short action. You will also want to remember that the increased bolt body diameter can cause feeding/magazine issues.
• Trigger hanger- I like the front hinge and only utilizing one fastener in the rear, but in general I’m not a fan of trigger hangers.
• Mirage hook- I’m not opposed to using a mirage strip and think it’s a neat touch but with the hook extending forward of the base it can cause complications with chassis that use a barrel shroud/handguard. I ended up having the mirage hook milled off so I could attach the XLR Carbon handguard.